How do I list a apt repository

Hi we have a installation of RedHat el which was built from source by our
parent company and is served out to us via a apt repo.

Is there any way i can list the actual contents of the repo to see if a file
is included?

For example I am looking for subversion within it but do not know if it was
called subversion, svn, subversion-1.2.1, or any other mangled name.

TIA,
Pep
.