RMS is "Ray Media Server" and it is only used for two things: Ray Video Recorder and Ray A/V chat.

     If you want to use those two things then YES you need it. If you don't need them then NO. If you are using a shared hosting account and you want these two things to work you have two choices, you can connect to the free Boonex RMS by checking that option in "Admin" under "Plug-ins" and then "Ray" and then "Base Options" or you can try to find someone else running a free (or paid) media server and connect to them. If you have a VPS or dedicated server you have more options, if that is the case you can run the "RMS" on your on server and not worry about connecting to anyone else.