Ground clearance is just the length between the ground to the lowest point on the car body.

Instead of looking at ground clearance, you should be looking at the maximum wading depth / flood fording depth.

That said, the best flood forders in your immediate budget are those that are pickup trucks/pickup-based.

Hilux
Fortuner
Strada
Montero
Ranger
Everest
Navarra
Dmax
MUX
Colorado
Trailblazer
etc etc