Hii
1. yes GST applicable on this situation , if landlord is registered then he is liable to pay gst and if he is not registered then tenant is liable to pay gst
2 in this situation gst is not applicable because residential property used for residential purpose then if out of GST
3. no gst on remuneration to Directors because its treated as salary
4 yes RCM is applicable subject to limit of Rs. 5000 per day as per section 9(4) of CGST Act , 2017