Now that the approval of the vaccine is in, some points:
The restricted approval (for SII/AZ) simply means that Serum Institute can neither sell to the private market nor can they export. Just saw an interview where Poonawalla said that he expects the vaccine to be supplied in the next week/10 days. Production will depend on government ability to lift the supply manufactured. Planned production is 50M per month. When the government eases restrictions, production will likely double.
Price to the government is ₹200 per shot. Price when available privately, probably in a couple of months, is about ₹1000 per shot. So ₹400 per person for the government and ₹2000 for a private individual.
Recommended gap by SII, for 90% efficacy is 2.5 months between shots.