Shaibal is right on target. If you're going to go to the trouble to
defragment then you may as well switch to uniform extent sizing so you don't
have the problem in the future.
If you have the room you can do it in stages. First create an index
tablespace and rebuild all your indexes in that.
Seema,
From your posting, it is not clear to me about the content of the mentioned tablespace. If it contains all of one users schema you can just take export for that particular schema. The step when you are recreating the tablespace, create it with pct increase 0 and do create initial and next
