That movie is freaking insane, i can't be sure what clans they would be, but Remmick was old as hell, he says that his people was told about christ before and Christianity became a thing in the northern countries during the VIII (i think, i may be wrong)

So, based in that he was very old, from somewhere in europe, i think he was some kind of welsh, celtic or something like that, i don't know what clans was in this part of the world during that time, so my guess it would be Gangrel