yes you can castle in 960
all basic rules ofcastle follows
Sometimes castling looks strange in Fischer Random chess, but try moving the king 2 or 3 squares over empty squares in the direction of the rook. Of course all the usual rules still apply, like the king and rook haven't moved before, king not in check etc.
Easiest way to castle in 960 is move the King on top of the rook you wish to castle with and let go. Say your starting position has your King on f1 and a Rook on h1. you move the piece on g1 out of the way and want to castle. It's true your King will end up on g1, but if you play Kg1, that's what will register, and castling won't. so, move your King to h1, on top of the rook as I explained, and castling is done.
Is there any way to castle in Chess960, and if so, how?