RMAN is the Oracle backup utility.  You can set it up and use it without any
interaction with TSM.  Think of it is a backup product that can back up to
local tape or disk.

When you add the TSM TDP, it just sort of makes TSM look like a funky tape
driver to RMAN.  YOu still run your backups and restores with RMAN, all your
functionality comes from there.  But instead of going to a local tape drive,
the data goes over the network to TSM.

What you need is (1) a license for the Oracle TDP, and (2) You also have to
install at least the API piece of the normal backup client, as both are
used.  You also need a separate TSM management class; they tell you in the
TDP install guide what the requirements are.  The data can go into your
normal disk storage pool, or direct to tape, just like any other TSM client
backup.

If you have never worked with an API-based TSM client, it is a bit different
than the backup client.  The api sends data to the TSM server, and TSM
treats it as a package and doesn't expect to know the contents.  TSM doesn't
do the normal versioning on Oracle backups; instead there is a utility you
run on the RMAN end when you want to expire old backups.  RMAN deletes the
versions from his catalog, then calls the TSM API to tell TSM what pieces to
delete from server storage.

The TDP install guide is pretty complete; the install is a bit messy, and
you have to follow the instructions EXACTLY.  But overall, it works very
well.

HOpe that helps..