Xine is a DVD player application. If you want to play RealMedia files, you need a media player like mplayer, which can play RealMedia video and audio files.
Go to the MPlayer website and download RPMs for your setup. If you do some Googling you can find a person who publishes an mplayer source RPM with the codecs bundled into it. I would post the URLs but I can't do that quite yet