How can I identify the point source of a borewell and the approximate depth of the borewell?

I want to drill a borewell in rural Nelamangala area in Bangalore. Water diviners use sticks, copper ring, coconut etc., to identify the source, which of these is reliable and believable? Is there a scientific way like hydro-geology or satellite mapping available for the use of common people in Bangalore area? In our case, water diviners had used sticks but no water was found at both the points they drilled. We drilled borewell at 450 ft and 600 ft and failed at both points. They have now promised water availability of about 3000 gallons at 350 ft and 500 ft. Can you please help me on this as I want to save the cost of borewell drilling at wrong places/points.