How to check the RigyBody that ground in different area

Unity Engine
1

how to check the Object that ground in different area. for the example i have a character and 2 areas A B , how to know that my character on area A or B? (C#)

2

You could give the areas different tags, and then use OnTriggerEnter like this:

function OnTriggerEnter (other : Collider){

	if ( other.tag == "a"){
            //Now the player is in area a
	}
}