Hello Janicelyn,
There are only a very small percentage of RealTracks that don't have 4 bar endings. "4 bar endings" means that the instrument stops playing in the 1st or 2nd bar of the ending, but the sound decays naturally for up to two more bars.
4 bar endings were added "retroactively" to older RealTracks, and a patch was made available for them in May of last year:
http://www.pgmusic.com/support_windows_realdrums.htm#RealTracks01-82If you already have the latest RealTracks files and "4 bar endings" aren't working in your song, it might be that your ending chord doesn't have a good sounding ending bar. Try a simpler chord like maj, maj7, min, or min7 and see if the ending sounds better then...
Also, make sure "use 4-bar endings for RealTracks" is enabled in the RealTracks preferences dialog.
If it's still not working for you, maybe you selected the wrong directory when you installed the patch.