When did the use of iron begin in Indian subcontinent?

During the Neolithic Age the earliest evidence of the origin of agriculture has been found at which of the following place in the North-Western region of Indian sub-continent?

The earliest evidence of man in India is found in

The three-age system, divided into stone, bronze and iron from the collection of Copenhagen museum was coined by –

According to the excavated evidence, the domestication of animal began in –

The Chalcolithic Ahar Culture has been identified in which of the following river systems?