The demand for coal in India is not projected to drop anytime soon. This is has nothing to do with the financial viability of coal power viz-a-viz other sources.

This is a combination of multiple factors

   - Indian coal is pretty poor quality and has lower energy density, imports could be better economically for power plants.
   - The true cost of mining with all the regulation and corruption is making imports cheaper for many plants. 
   - Major mining players are grappling with huge debt and do not necessarily have the ability to take up new projects
   - Coal India a government owned entity controls most of the market and transportation is dependent on Indian Railway also fully government owned, other contracts/ services have to be also favorable/in-place to make a mine viable