>How can i delete a file which resides on 3590 tape?

If it was via a Backup, you don't directly delete it: TSM policies
expire it.  If it was an Archived file, you use the B/A client
to delete the instance.

I'd strongly recommend reading the TSM documentation to get more
familiar with the product you are trying to use.  Start with the
Backup/Archive Clients manual, and then review the Admin manual.