to run Real media (rmvb)
 

which app can run rmvb files (without "movie player".. i m looking for a good app ) or how can we do it by similar programs like mplayer ..

codecs , etc.. ?

dist : debian

Try Vlc to start with from the Debian repositories.
If this does not work then there is a Real media .deb available:

http://www.real.com/linux