Second, you need to install RPG mod. Here's the files. RPG Mod
You should now be able to play Tribes and the RPG mod. When you start the game and you create a name, make sure you put a password into the
"otherinfo" field on the player creation screen. Without that, you wont be able to join any rpg servers. Once you have everything installed, then
go into the game and start to query the server list. Find Sinister's Wasteland and join that server. Make sure you are not joining Iceworld because
at this point you do not have the files to play that server.
If you would like to update your tribes so that you can play on the Iceworld server, then you must download the iceworld updater located on
THIS page.