The hotel is conveniently located in the transit zone so you can use it only if you are connecting between two international flights. To find it, pass the security of transit flights and then search the KFC in the food court of the departure zone and behind is the lift for the hotel. So no Indian visa required.
Unfortunately, the staff is a problem. They replied to my message asking about the visa 4 days later and without answering my question and never answered my second message via hotels.com. Once in the airport, they couldn't explain to me how to reach the hotel on the phone! Unbelievable!
The hotel room is ok but no windows and because it is one level under the food court, you can hear all the night the noise of the chairs that multiple people pulled all the time.
At the end, just convenient but nothing more