GST - RCM - for Commercial Building Rent

I have taken  hostel Franchise with Amigo  and from Oct 25 collecting  5% GST without ITC - Rent below 7500/- - and i have takne the building lease with unregistered person MOnthly Rent Rs.200000 and decuting IT tDS - 20000  i want to know i want to pay RCM for Rent 2,00,000 - RCM AMount 18% - 36000 in GST or not and if i pay the RCM and can avail the RCM paid ITC and adjust the amount with OUtput Tax 5%  - all other ITC Commisson , purchase are showning as ineligible ITC because collection 5% Tax Without ITC - Kinldy do the needful