rpm's don't work very well. The self extracing binary always works, so go here
and get the self extracting binary. Change tha permissions on it so you can execute it
chmod 755 /path/to/j2re-*
Then cd into the folder where you want to install it. That's up to you. If you want to install it system side you'll need to become root so I find it's easiest to just install it in my home folder.
Agree to the terms and that bit is done. Now, to install the plugin,
install -d ~/.mozilla/plugins
ln -s /some/folder/or/other/j2re*/plugin/i386/ns610-gcc32/libjavaplugin_oji.so