Reparing Roof of rented room

Facts: Since long our landlord has taken rent due to dispute w,r,t to increase in amount of rent. In begining we used to deposit the rent to rent control but later we also stopped depositing payment to rent control (may be due to casully). Now the prob is condition of roof of one of the room is so worse that it may lead to incident and it may cause hazardous to human life. For this along with dispute issue, we approached to landlord and now he is ready to settle rent amount dispute and also told orally to renovate the room. Now my ques are: 1. whether rent control office can refund the amount of rent deposited. If yes, then what is the procedure and documents required.. 2. Since landlord is ready orally, still for safe side what permissions are required to take from Kolkata Muncipal corporation and other authorities so that any authority do not prevent us to renovate the room(at 1st floor) 3. What to do if someone frm KMC or police comes even after taking permission from councilor. 4. any suggestion