Rules are essentially the same, and the king and rook being castled with go in the same places they would in a normal game (so king on c1 (c8 for black) and rook on d1 (d8 for black) for a-side castling and king on g1 (g8 for black) and rook on f1(f8 for black) for h-side):
https://support.chess.com/customer/en/portal/articles/1444897-how-do-i-castle-in-a-chess960-game-
What are the rules for castling in Chess 360 games? I have a king on what would normally be the king bishop initial position, and a rook on the king rook initial position. Neither has moved, I'm not in check, etc., so the normal rules that allow castling would be in play. Would the king move the two spaces toward the rook, therefore landing on the rook, and the rook move one space toward the king?