Looking at population density of India, I don't think it's population issue. You mentioned overpopulation in your response to India's problem. I assure you, India can grow as rich as US even at 3 billion population.

India has many problems but population at present in not one of those, maybe it will become a problem if population growth is kept uncheck. But don't blame slow development in past and present to population.

Population being accumulated in few cities is a problem of government and their failure to understand how market works and how they can better it.

None of the political party in India have any viable development plan.