In Africa it costs 2.5 million USD to build 1 km of metalled single carriageway road, I have no reason to expect the cost to be significantly different in India.
Maintenance is another 1,000 to 5,000 USD per annum per km.
The cost of 1km of road would provide a dozen villages with drones and full support and have a few hundred thousand USD left over.
The cost of upgrading the existing dirt track network to fully metalled roads would never be sensible expenditure from a cost/benefit point of view - spending $50m to connect a couple of villages 20km apart for maybe 250 people makes zero economic sense.