All GNU/Linux distros are modular
in nature. So you will find that all the multimedia players will support prepriatory formats when the appropriate codecs are installed and all will play encrypted
DVDs if libDVDcss is installed.
For instance, I play the full range of multi-media, including encrypted DVDs, with totem-xine.
In general, Xine-engine players are favored, though the gstreamer engine is pretty good.
Amarok is an excellent, full featured, audio-only player.
Still favorites are MPlayer and XMMS.
However - free formats are usually superior to, and better supported than, non free ones. Fortunately you can rip directly to vorbis or flacc, or you can convert any ffmpeg supported format to them with ffmpeg2theora.
Your first port of call when considering these things for RHEL will be the up2date servers.
Note: RHEL is a commercial distro with paid support. If you want free support, it is best to use a free distro.
For fedora, all these and more are available via yum.