Plugins help!!!
 

I'm using RHEL 5.1
I'm trying to play mp3 music. It is saying that:

Totem could not play 'file:///home/Solitude/Mp3 Pieces/METALLICAEnterSandman.mp3'.

You do not have a decoder installed to handle this file. You might need to install the necessary plugins.


What to do now?

Redhat does not distribute some codecs needed to play back restricted media types.
You must either install the codecs yourself (which action may be illegal in your country) or transcode the file to a Free or Open format, which totem can legally handle.

The utility ffmpeg2theora works well to transcode files. I suggest ogg/vorbis or flac format.

You install new software and some codecs to RHEL with up2date. When you have a commercial distribution, it is best to use the commercial support - you are paying for it afher all.

If you prefer to have free support, it is more logical to use a free distribution - consider CentOS or fedora. Both these are easier to install things to.

How to get?
 

Yes I can download.
But which is good?
Can anybody suggest me where I can find it?

try mp3blaster
http://mp3blaster.sourceforge.net/

What do you mean "which is good"? Do you have a choice of different codec packages?

People can give you a lot of choices of media player for your computer.
They all use the same codecs.

As I said, search the up2date repos for restricted multimedia codecs.