Rate of Tax - Goods and Services Tax - GST

Dear Experts, One of my clients who is having a hall and giving free of cost but charging only for the food supply for any function. He charges the GST tax only on food @ 5% and no seperate consideration received for hall. Another client runs the hotel and provides breakfast for a complement which is included in the room rent. He charges the GST tax only on the Room rent @ 12% but no separate consideration is received for food and drinks. Please let me know whether this procedure is correct with the rate of tax or something else. Please advise me on this. Thanks in Advance.