I recently installed the latest RFC MP mod for v3.19 but when I opened up a hotseat game and went to 600AD start I wasen't allowed to be any european civs, all civs after the Arabs were taken out! Can someone please explain this? thanks:)

MP works a bit differently. There is a .pdf file included in the download that goes over some of the differences including civ selection. In this version unfortunately you can't AI autoplay up to the civ you want to control. You will have to play the game with another civ until the civ you want spawns upon which, you save the game and reload choosing the new civ.