Get the rotation of a collided object [3D]?

I'm using a character controller, and i want to know if the player is currently standing on something so it can jump, but i don't want to use tags or ground layers to every object that the player can stand on, becouse i want him to stand on anything always that object has a sertain rotation. So, i want to get the component rotation of the object the player is currently standing on, is there any function or something that already does this?