In India there are four mints:
1. Mumbai (Bombay) Mint
2. Kolkatta (Calcutta) Mint
3. Noida Mint
4. Hyderabad Mint

The circulating coins bear the marks below year:

1. Diamond shape below year - Mumbai Mint
2. No marks below year - Kolkatta Mint
3. A dot below the year - Noida Mint
4. A star below the year - Hyderabad Mint

The Proof coins/uncirculating coins bear differ in the marks shown, but these above are the marks from Mints in India.