Last month I used my Platinum card for FHR booking through Amex Travel portal. I was making this booking in my phone while commuting. My booking amount was INR 143000, and accidentally "Pay with Points" option got selected with 36,800 points (equivalent to INR 9200) for redemption.
The booking...
The list has the name as "NIT Karnataka", you wrote "NIT Surathkal". I think they don't know that both are same, and concluded that your Institute is not in the list. Worth trying again with "NIT Karnataka".