SELECT stuid, percentage, rank() over (parition by class order by percentage desc) as pos
FROM (SELECT stuid, sum(obtained marks) / sum(possible marks) * 100 as percentage
      FROM .....
      WHERE .....
      GROUP BY stuid
     )

select distinct sub.sno,test1.obtmarks,test1.perct,test.examc, test.totmarks,test.class|| '/' ||test.sec sec, sub.subject,student.stuid, ' '||student.name name
 from sub,test1, test, student,class
 where ltrim(test.subject)=rtrim(sub.subject)
 and test.class=class.cname
 and class.cname=sub.cname
 and  test1.tdate = test.tdate
 and test.tid = test.tid
 and student.stuid = test1.tstuid
 and student.status='PRESENT'
 and test.examc=:ty
 and student.class=:cls
and section=:ssec

union all

select percentage, rank() over (partition by :cls order by percentage desc) as pos
from (select sum(obtmarks)/sum(totmarks) * 100 as percentage,sub.sno,test1.obtmarks,test1.perct,test.examc, test.totmarks,test.class|| '/' ||test.sec sec, sub.subject,student.stuid, ' '||student.name name
  from test1,test,student,class,sub
  where test1.tid=test.tid 
  and test1.tdate=test.tdate
  and LTRIM(TEST.subject)=RTRIM(SUB.SUBJECT)
  and test.class=class.cname
  and class.cname=sub.cname
  and student.stuid = test1.tstuid
 and student.status='PRESENT'
      group by stuid,sub.sno,test1.obtmarks,test1.perct,test.examc, test.totmarks,test.class|| '/' ||test.sec, sub.subject,student.stuid, ' '||student.name
     )
order by sub.sno

SELECT  distinct sub.sno,TEST1.OBTMARKS, TEST1.PERCT,  
TEST.EXAMC, TEST.TOTMARKS, TEST.CLASS|| '/' ||TEST.SEC sec, 
SUB.SUBJECT, STUDENT.STUID, ' '||STUDENT.NAME name,
(select percentage,rank() over (partition by class order by stuid) 
as pos from (select percentage sum(obtmarks)/sum(totmarks)*100 
from test,test1 where test.tid=test1.tid and test.tdate=test1.tdate
and test.class=:cls)
FROM sub,TEST1, TEST, STUDENT,class
WHERE LTRIM(TEST.SUBJECT)=RTRIM(SUB.SUBJECT)
AND TEST.CLASS=CLASS.cname
and class.cname=sub.cname
and TEST1.TDATE = TEST.TDATE
 AND TEST1.TID = TEST.TID
 AND STUDENT.STUID = TEST1.TSTUID
and student.status='PRESENT'
and test.examc=:ty
and student.class=:cls
and section=:ssec
order by sub.sno

(select percentage,rank() over (partition by class order by stuid) AS pos 
 from (select percentage sum(obtmarks)/sum(totmarks)*100 
       from test,test1 
       where test.tid=test1.tid 
       and test.tdate=test1.tdate
       and test.class=:cls)

select perc,rank() over (partition by class,SEC order by stuid) AS pos,class,stuid,
examc,sec
from (select sum(obtmarks)/sum(totmarks)*100 As perc, student.class,stuid,
   examc,sec
       from test,test1,class,sub,student
       where test.tid=test1.tid
       and test.tdate=test1.tdate
       and test.class=student.class
       and test.sec=student.section
       and test1.tstuid=student.stuid
       and student.STATUS='PRESENT'
       and sub.subject=test.subject
       and sub.cname=class.cname
       and examc=test.examc
       group by student.class,stuid,examc,sec)

SELECT DISTINCT SUB.SNO, VIE.POS,TEST1.OBTMARKS, TEST1.PERCT, TEST.EXAMC, 
TEST.TOTMARKS, TEST.CLASS||'/'||TEST.SEC See, SUB.SUBJECT, STUDENT.STUID, 
' '||STUDENT.NAME DIS FROM SUB, TEST1, TEST, STUDENT, CLASS, VIE
WHERE (STUDENT.STATUS = 'PRESENT'
 AND TEST.EXAMC = :ty
 AND STUDENT.CLASS = :cls
 AND STUDENT.SECTION = :ssec)
 AND ((SUB.CNAME = CLASS.CNAME)
 AND (TEST.CLASS = CLASS.CNAME)
 AND (TEST1.TDATE = TEST.TDATE)
 AND (TEST1.TID = TEST.TID)
 AND (STUDENT.STUID = TEST1.TSTUID)
 AND (TEST.SUBJECT = SUB.SUBJECT))
 AND VIE.examc=:ty
 AND VIE.CLASS=:CLS
 AND VIE.SEC=:SSEC
 AND VIE.STUID=STUDENT.STUID
AND VIE.STUID=TEST1.TSTUID
ORDER BY SUB.SNO

create function po (pos IN NUMBER)
     RETURN NUMBER
     IS pos NUMBER(3);
     BEGIN
     select perc,rank() over (partition by class,sec,examc order by perc) into pos
     from (select sum(obtmarks)/sum(totmarks)*100 As perc, student.class,stuid,
     examc,sec,sub.subject
         from test,test1,class,sub,student
         where test.tid=test1.tid
         and test.tdate=test1.tdate
         and test.class=student.class
         and test.sec=student.section
         and test1.tstuid=student.stuid
         and student.STATUS='PRESENT'
         and sub.subject=test.subject
         and sub.cname=class.cname
         and examc=test.examc
         group by student.class,stuid,examc,sec,sub.subject);
     RETURN(pos);
      END po;

SQL> show errors
Errors for FUNCTION PO:

LINE/COL ERROR
-------- -----------------------------------------------------------------
0/0      PL/SQL: Compilation unit analysis terminated
1/1      PLS-00410: duplicate fields in RECORD,TABLE or argument list are
         not permitted

SELECT DISTINCT SUB.SNO, VIE.POS,TEST1.OBTMARKS, TEST1.PERCT, TEST.EXAMC, 
TEST.TOTMARKS, TEST.CLASS||'/'||TEST.SEC See, SUB.SUBJECT, STUDENT.STUID, 
' '||STUDENT.NAME DIS FROM SUB, TEST1, TEST, STUDENT, CLASS, VIE
WHERE (STUDENT.STATUS = 'PRESENT'
 AND TEST.EXAMC = :ty
 AND STUDENT.CLASS = :cls
 AND STUDENT.SECTION = :ssec)
 AND ((SUB.CNAME = CLASS.CNAME)
 AND (TEST.CLASS = CLASS.CNAME)
 AND (TEST1.TDATE = TEST.TDATE)
 AND (TEST1.TID = TEST.TID)
 AND (STUDENT.STUID = TEST1.TSTUID)
 AND (TEST.SUBJECT = SUB.SUBJECT))
 AND VIE.examc=:ty
 AND VIE.CLASS=:CLS
 AND VIE.SEC=:SSEC
 AND VIE.STUID=STUDENT.STUID
AND VIE.STUID=TEST1.TSTUID
ORDER BY SUB.SNO

CREATE OR REPLACE FORCE VIEW VIE (
select perc,rank() over (partition by class,SEC order by perc DESC) AS pos,class,sec
,examc
from (select sum(obtmarks)/sum(totmarks)*100 As perc,student.class,test.examc,
test.sec
       from test,test1,class,sub,student
       where test.tid=test1.tid
       and test.tdate=test1.tdate
       and test.class=STUDENT.CLASS
       and test.sec=STUDENT.SECTION
       and test1.tstuid=student.stuid
       and student.STATUS='PRESENT'
       and sub.subject=test.subject
       and sub.cname=class.cname
       and examc=TEST.EXAMC
       group by student.class,examc,sec,STUID)

SELECT DISTINCT SUB.SNO, TEST1.OBTMARKS, TEST.EXAMC, TEST.TOTMARKS, TEST.CLASS||'/'||TEST.SEC See, SUB.SUBJECT, STUDENT.STUID, ' '||STUDENT.NAME DIS,VIE.POS,vie.perc
 FROM SUB, TEST1, TEST, STUDENT, CLASS,VIE
WHERE (STUDENT.STATUS = 'PRESENT'
 AND TEST.EXAMC = :ty
 AND STUDENT.CLASS = :cls
 AND STUDENT.SECTION = :ssec)
 AND ((SUB.CNAME = CLASS.CNAME)
 AND (TEST.CLASS = CLASS.CNAME)
 AND (TEST1.TDATE = TEST.TDATE)
 AND (TEST1.TID = TEST.TID)
AND VIE.CLASS=:CLS
AND VIE.SEC=:SSEC
and vie.stuid=student.stuid
AND VIE.EXAMC=:TY)
 AND (STUDENT.STUID = TEST1.TSTUID)
 AND (TEST.SUBJECT = SUB.SUBJECT)
ORDER BY SUB.SNO

CREATE OR REPLACE FORCE VIEW VIE
(
  PERC, POS, CLASS, SEC, EXAMC, STUID
)
AS 
select perc,rank() over (partition by class,SEC,examc order by perc DESC NULLS LAST) AS pos,class,sec
,examc,stuid
from (select sum(obtmarks)/sum(totmarks)*100 As perc,student.class,test.examc,
test.sec,student.stuid
       from test,test1,class,sub,student
       where test.tid=test1.tid
       and test.tdate=test1.tdate
       and test.class=STUDENT.CLASS
       and test.sec=STUDENT.SECTION
       and test1.tstuid=student.stuid
       and student.STATUS='PRESENT'
       and sub.subject=test.subject
       and sub.cname=class.cname
       and examc=TEST.EXAMC
       group by student.class,examc,sec,STUID)
/

SELECT t.*, rownum FROM 
(QUERY THAT GIVES STUDENTS WITH RANK ORDERED BY RANK DESCENDING) t
WHERE ROWNUM < 3

select perc,rank() over (partition by class,SEC,EXAMC order by perc DESC NULLS LAST) AS pos,
stuid,class,sec,examc
from (select sum(obtmarks)/sum(totmarks)*100 As perc,student.class,stuid,test.examc,
test.sec
       from test,test1,class,sub,student
       where test.tid=test1.tid
       and test.tdate=test1.tdate
       and test.class=student.class
       and test.sec=student.SECTION
       and test1.tstuid=student.stuid
       and student.STATUS='PRESENT'
       and sub.subject=test.subject
       and sub.cname=class.cname
       and examc=test.EXAMC
       group by student.class,examc,sec,STUID)
order by stuid
/

select distinct perc,rank() over (partition by class,SEC,EXAMC order by perc DESC NULLS LAST) AS pos,
stuid,class,sec,examc
from (select distinct sum(obtmarks)/sum(totmarks)*100 As perc,student.class,stuid,test.examc,
test.sec
       from test,test1,class,sub,student
       where test.tid=test1.tid
       and test.tdate=test1.tdate
       and test.class=student.class
       and test.sec=student.SECTION
       and test1.tstuid=student.stuid
       and student.STATUS='PRESENT'
       and sub.subject=test.subject
       and sub.cname=class.cname
       and examc=test.EXAMC
       group by student.class,examc,sec,STUID)
order by stuid

SQL> ED
Wrote file afiedt.buf

  1  SELECT SUM(TOTMARKS) FROM TEST
  2* WHERE CLASS='FOUR' AND SEC='WHITE' AND EXAMC='1ST ASSESSMENT OF 2ND TERM'
SQL> /

SUM(TOTMARKS)
-------------
          210

SQL> ed
Wrote file afiedt.buf

  1  SELECT SUM(round(TEST1.OBTMARKS)) FROM TEST1
  2  where tid in (1786,1836,1898,2055,2056,2057,2137,2138,2169)
  3* and tstuid=1003
SQL> /

SUM(ROUND(TEST1.OBTMARKS))
--------------------------
                       185

CREATE OR REPLACE FORCE VIEW VIE
(
  PERC, POS, CLASS, SEC, EXAMC, STUID
)
AS 
select perc,rank() over (partition by class,SEC,examc order by perc DESC NULLS LAST) AS pos,
 class,sec,examc,stuid
 from(select sum(round(test1.obtmarks))/sum(totmarks)*100 as perc,stuid,student.class,
 test.examc,test.sec
 from test,test1,student,class
 where test.class=student.class and test.sec=student.section and examc=test.examc
 and test.tid=test1.tid
 and test1.tstuid=student.stuid
 and student.status='PRESENT'
 and class.cname=test.class
 and class.cname=student.class
 and test.sec=student.section
 group by test.examc,student.class,test.sec,student.stuid)
 order by stuid

SQL> desc test
 Name                                      Null?    Type
 ----------------------------------------- -------- ----------------------------
 TID                                       NOT NULL NUMBER(9)        --Primary key (Composite)
 TDATE                                     NOT NULL DATE             --Primary Key (Composite)
 CLASS                                              VARCHAR2(30)
 EXAMC                                              VARCHAR2(80)
 SUBJECT                                            VARCHAR2(70)
 TOTMARKS                                           NUMBER(3)
 SEC                                                VARCHAR2(50)

SQL> desc test1
 Name                                      Null?    Type
 ----------------------------------------- -------- ----------------------------
 TID                                                NUMBER(9)        -- Foreign Key
 TDATE                                              DATE             -- Foreign Key
 TSTUID                                             NUMBER(7)
 OBTMARKS                                           NUMBER(5,2)
 PERCT                                              NUMBER(6,2)
 REMARK                                             VARCHAR2(300)

select 
  perc,
  rank() over (partition by class, SEC, examc order by perc DESC NULLS LAST) AS pos,
  ...

Create table test (
  tid number(9),tdate date, class varchar2(30),examc varchar2(80),subject varchar2(70),
  totmarks number(3),sec varchar2(50),
  constraints test_pk primary key (tid,tdate));
insert into test (tid,tdate,class,examc,subject,totmarks,sec)
  values
 (1,'23-SEP-2014','KG','1st Term Exams','English',50,'A');

 insert into test (tid,tdate,class,examc,subject,totmarks,sec)
 values
 (2,'23-SEP-2014','KG','1st Term Exams','Math',50,'A');

 insert into test (tid,tdate,class,examc,subject,totmarks,sec)
 values
 (3,'23-SEP-2014','KG','1st Term Exams','Urdu',40,'A');

Create table test1 (
  tid number(9),tdate date,tstuid number(7),obtmarks number(5,2),perct number(6,2),
  remark varchar2(300),constraints test_fk foreign key (tid,tdate) references  
  test(tid,tdate));

 insert into test1 (tid,tdate,tstuid,obtmarks,perct,remark)
 values
 (1,'23-SEP-2014',22,40,80.00,'Good');

 insert into test1 (tid,tdate,tstuid,obtmarks,perct,remark)
 values
 (1,'23-SEP-2014',23,33,66.00,'Good');

 insert into test1 (tid,tdate,tstuid,obtmarks,perct,remark)
 values
 (2,'23-SEP-2014',24,25.5,51.00,'Average');
 insert into test1 (tid,tdate,tstuid,obtmarks,perct,remark)
 values
 (2,'23-SEP-2014',22,33,70.00,'Good');

 insert into test1 (tid,tdate,tstuid,obtmarks,perct,remark)
 values
 (2,'23-SEP-2014',23,33,66.00,'Good');

 insert into test1 (tid,tdate,tstuid,obtmarks,perct,remark)
 values
 (2,'23-SEP-2014',24,25,51.00,'Average');

 insert into test1 (tid,tdate,tstuid,obtmarks,perct,remark)
 values
 (3,'23-SEP-2014',22,40,80.00,'Good');

 insert into test1 (tid,tdate,tstuid,obtmarks,perct,remark)
 values
 (3,'23-SEP-2014',23,33,66.00,'Good');

 insert into test1 (tid,tdate,tstuid,obtmarks,perct,remark)
 values
 (3,'23-SEP-2014',24,25.5,51.00,'Average');

Create Table Class (
Cname varchar2(70) primary key);

  Insert into class (cname) values ('KG');
  Insert into class (cname) values ('I');
  Insert into class (cname) values ('II');
 
Create table sub (
 cname varchar2(70) references class(cname),sno number(3),subject varchar2(70));

 Insert into sub (cname,sno,subject)
 values 
 ('KG',1,'English');
 Insert into sub (cname,sno,subject)
 values 
 ('KG',2,'Math');
 Insert into sub (cname,sno,subject)
 values 
 ('KG',3,'Urdu');
 Insert into sub (cname,sno,subject)
 values 
 ('I',1,'English');
 Insert into sub (cname,sno,subject)
 values 
 ('I',2,'Math');
 Insert into sub (cname,sno,subject)
 values 
 ('I',3,'Urdu');

create table student (
 stuid number(7) primary key,status varchar2(30),class varchar2(30),section varchar2(30),name varchar2(200),fname    
 varchar2(200));

Insert into student (stuid,status,class,section,name,fname)
values 
(22,'PRESENT','KG','A','ALI','MMM');
Insert into student (stuid,status,class,section,name,fname)
values 
(23,'PRESENT','KG','A','ABB','CMM');
Insert into student (stuid,status,class,section,name,fname)
values 
(24,'PRESENT','KG','A','AII','MCC');
Insert into student (stuid,status,class,section,name,fname)
values 
(25,'PRESENT','KG','A','AAA','CCC');
Insert into student (stuid,status,class,section,name,fname)
values 
(26,'PRESENT','KG','A','ALL','CDC');
Insert into student (stuid,status,class,section,name,fname)
values 
(27,'PRESENT','KG','A','VVV','CXWE');

SQL> with test as
  2    (select 223 stud_id, 58 total_no from dual union all
  3     select 315 stud_id, 75 total_no from dual union all
  4     select 423 stud_id, 75 total_no from dual union all
  5     select 583 stud_id, 83 total_no from dual
  6    )
  7  select
  8    stud_id,
  9    rank() over (order by total_no) l_rank,
 10    dense_rank() over (order by total_no) l_dense_rank
 11  from test;

   STUD_ID     L_RANK L_DENSE_RANK
---------- ---------- ------------
       223          1            1
       315          2            2
       423          2            2
       583          4            3

SQL>

SELECT DISTINCT SUB.SNO, TEST1.OBTMARKS, TEST.EXAMC, TEST.TOTMARKS, TEST.CLASS||'/'||TEST.SEC See, SUB.SUBJECT, STUDENT.STUID, ' '||STUDENT.NAME DIS,VIE.POS,vie.perc
 FROM SUB, TEST1, TEST, STUDENT, CLASS,VIE
WHERE (STUDENT.STATUS = 'PRESENT'
 AND TEST.EXAMC = :ty
 AND STUDENT.CLASS = :cls
 AND STUDENT.SECTION = :ssec)
 AND ((SUB.CNAME = CLASS.CNAME)
 AND (TEST.CLASS = CLASS.CNAME)
 AND (TEST1.TDATE = TEST.TDATE)
 AND (TEST1.TID = TEST.TID)
AND VIE.CLASS=:CLS
AND VIE.SEC=:SSEC
and vie.stuid=student.stuid
AND VIE.EXAMC=:TY)
 AND (STUDENT.STUID = TEST1.TSTUID)
 AND (TEST.SUBJECT = SUB.SUBJECT)
ORDER BY SUB.SNO