I have lost count of the number of times I have tried to install an RPM only to find that it has lots of dependencies and it takes a dozen or so attempts before I get to install it. If you use the "-qpR" flag you can actually see the contents of a package and its dependencies just by examining the RPM.
In this example you should only need to install "krb5-libs".
# rpm -qpR ./krb5-workstation-1.9.4-1.aix5.1.ppc.rpm
krb5-libs = 1.9.4-1