select * from
(
select Row_Number() over(Partition by KitComponentID,Created_on order by KitComponentID,Created_On desc) as SrNo, *
from tblnm
) as tmptbl
where SrNo=1
for sql 2000
select *
from tblnm t1 where t1.stgID = (select top 1 stgid from tblnm t2 where t2.KitComponentID = t1.KitComponentID order by Created_On desc)
Happy Coding!
:)