It is suggested that you first check the rate of tax payable. In case of mandap keeper service being an event based catering - it would be an outdoor catering services under GST as per the rate notification
In such case, if it is provided by a person/ at a place - not providing accommodation services with > ₹ 7,500 declared tariff - then there is no choice but to pay GST @5%. In such case no ITC would be eligible.
However, if the rate of tax is to be 18% as per the rate notification, then the ITC of AMC, repair work would be eligble since these are not capitalised.