Gst on hotels

GST will be computed on the actual tariff but only to decide the tax rate, declared tariff is to be seen.
For example:-
Case 1: Declared tariff is Rs. 1400
Actual tariff is Rs. 1700
GST will be applicable as declared tariff is more than Rs. 1000. So GST will be 12% on 1700 = 204.

Case 2: Declared tariff is Rs. 900
Actual tariff is 1100
GST will not be applicable as declared tariff is less than Rs. 1000.

If hotel display rate is 7500 and on that they are giving discount of 2500, what will be the GST rate ????