Probably not.the hole in the wall i have is exactly 6"x8" will it fit,will the screws line up?
The fixing holes are in each corner, and the usual method of installing that type of fan is to drill a round hole in the wall of appropriate size, which will therefore leave enough wall material in the corners to drill holes for fixing screws.
However a solution is to cut a piece of 1/2 inch plywood to the size of the hole you have, cut a round hole in it, fix the plywood in the wall hole and then screw the fan onto the plywood. Tiling and other decoration optional.

