While transferring money from the US to India, you can either use locked-in exchange rates or indicative exchange rates. The only difference between these exchange rates is that you will know the exact amount of money that will be received by the recipient when you send money, with locked-in rates. On the other hand with indicative rates, you are not aware about it, as the exchange rate will be determined at the time of money transfer based on the Foreign-Exchange.
For example: If exchange rate on the day of transferring money is 55 rupees for 1USD, your recipient will receive an exact amount of 5500 INR, with locked-in rates. But, if you use indicative rates, the exchange rate is determined at the time of money transferred, as bank may not send money the same day you did the transaction.
To learn more about their differences, visit Locked-in Exchange Rates Vs. Indicative Exchange Rates