Efficient Water Pump

You don't say how deep the well is, or the diameter, but there's a good bet the pump will be submersible, borehole type or guide rail mounted. I would get quotes from several suppliers and check which has highest efficiency.

pump should be surface mounted,motor driven,depth 20ft with footvalve,well diameter 12 ft

If it's 20ft lift from the water surface to pump suction you'll need to watch the NPSH, so work that out and tell the pump suppliers. Various types of pump could be used, depending on flowrate. Get some quotes. Axial flow pumps tend to have high efficiency, but 60ft head might be on the high side, unless it's a very high flow.

A centrifugal pump will likely be your best choice but they work best with a suction head of no more than about 15 feet, below that their performance drops markedly.

With a well depth of 20 feet you are going to get better results if the pump assembly is at the bottom of the well. The motor can still be at the top by using a shaft driven vertical sump pump such as a Goulds model 3171 or similar that can handle pit depths of 20 feet or more, with a head of up to around 350 feet and capacities up to about 700 m³/h.

suppose we fix it 5ft into the well on a concrete slab with vertical lift of 15ft only which kind of pump will consume lowest power and supply most amount of water.

Highly insufficient data.

You really need to be on the phone to pump suppliers rather than wasting your time here, Mildred.

pump supplier will quote for what he has only, but form should give best solution

You don't understand.

Any, "pump supplier will quote for what he has only".

If you think anyone is going to build a SINGLE custom pump for you, you are delusional.

You will get what the (any) pump supplier has available, and nothing more.

So, call three pump suppliers and give them much more information than you gave us.

Otherwise, you are wasting the forum's, and your, time.

Agreed, tell them at least -

Flowrate

Depth of water (irrelevant unless it's very shallow, but tell them anyway)

Height from water surface to pump inlet (if the pump is at ground level, as you say you want)

Variation in above height

I'm with Tornado.

No way to tell from what's given.

Little things like suction head, flow rate, etc.