P.S. I started looking into Hilton affiliates in India. This is what I got so far from the HH folks...

Thank you for your e-mail.

Our records were unable to locate any HHonors hotels in India. I
suggest you contact Diamond Special Services as the HHonors service center
does not have access to reservations details and information.

I sincerely apologize for the inconvenience this may cause.

Thank you and best regards,
Chanda