for starters if you are needing to install a foo.rpm file use yum instead.
# yum install foo.rpm
second of all, in order to find exactly were something is mounted, and I am guessing you mean RHE3 when you say RC3, there was no automagical mount in RHE3. that did not come about until late RHE4 and early RHE5.
as either user or root to see exactly were you have things mounted. from there you can ls -l, thats a lower case L, not a one, to LIST the files in that location.