What is the GST Registration and Rate provision on Marriage Palace (Marriage garden and 15 Rooms).

Reply—Rate of GST will be 5% on Catering of food, banquet facilities and combination of both in self owned marriage and party halls by Hotel having all rooms below Rs. 7,500 per room per day. (Refer advance ruling pronounced by AAR Haryana in matter of Jewel Classic Hotels dated 25.06.2020)

However, if rent of a room is more than Rs. 7500/- per day, it will be taxable @18%. 

As stated in your question if taxpayer is providing only accommodation service as renting of marriage garden and rooms without any catering facility, it will be considered as supply of service by way of renting of commercial property and taxable @18% with ITC benefit.