Isn't DENSE_RANK() OVER (partition by c_id, name ... ) what you want?

with WorkView as (
SELECT 'GULSU1' NAME, 111 C_ID,10 as SortKey FROM DUAL UNION
SELECT 'GULSU1', 111,20 FROM DUAL UNION
SELECT 'GULSU1', 111,30 FROM DUAL UNION
SELECT 'GULSU1', 111,40 FROM DUAL UNION
SELECT 'GULSU1', 111,50 FROM DUAL UNION
SELECT 'GULSU1', 111,60 FROM DUAL UNION
SELECT 'GULSU1', 111,70 FROM DUAL UNION
SELECT 'GULSU1', 111,80 FROM DUAL UNION
SELECT 'GULSU1', 111,90 FROM DUAL UNION
SELECT 'GULSU2', 112,100 FROM DUAL UNION
SELECT 'GULSU2', 112,110 FROM DUAL UNION
SELECT 'GULSU2', 112,120 FROM DUAL UNION
SELECT 'GULSU2', 112,130 FROM DUAL UNION
SELECT 'GULSU2', 112,140 FROM DUAL UNION
SELECT 'GULSU2', 112,150 FROM DUAL UNION
SELECT 'GULSU2', 112,160 FROM DUAL UNION
SELECT 'GULSU1', 112,170 FROM DUAL UNION
SELECT 'GULSU1', 112,180 FROM DUAL)
select NAME,C_ID,SortKey,
sum(willSum) over(partition by NAME order by SortKey) as version
from (select NAME,C_ID,SortKey,
       case when lnnvl(NAME = Lag(NAME) over(order by SortKey))
            then 1 else 0 end as willSum
       from WorkView)
order by SortKey;

NAME    C_ID  SortKey  version
------  ----  -------  -------
GULSU1   111       10        1
GULSU1   111       20        1
GULSU1   111       30        1
GULSU1   111       40        1
GULSU1   111       50        1
GULSU1   111       60        1
GULSU1   111       70        1
GULSU1   111       80        1
GULSU1   111       90        1
GULSU2   112      100        1
GULSU2   112      110        1
GULSU2   112      120        1
GULSU2   112      130        1
GULSU2   112      140        1
GULSU2   112      150        1
GULSU2   112      160        1
GULSU1   112      170        2
GULSU1   112      180        2

On Oracke9i,
we must emulate lnnvl.

similar thread
450745

and my site :-)
http://www.geocities.jp/oraclesqlpuzzle/10-130.html