Thank you for your anwser.
Just like a window. Sorry i don't know what kind of this rectangle called in english
but i have got an idea
just put position2d node to the top left corner and bottom right corner
and then get global position of them and random between position x and y of 2 node
var random_x = rand_range(position1.x,position2.x)
var random_y = rand_range(position1.y,position2.y)