Issues with Joint ownership

I had inherited an apartment in Ahmedabad after the death of my Mother. It is to be share equally with my sister and the property is now transferred to our joint names. Our aunt was living there but has now moved and I wanted to sell the property. My sister and I are not on talking terms anymore and my brother in law speaks on her behalf. We both reside outside India. In December last year I was visiting India and asked my brother in law to be there so we could sell the property but he was being unreasonable and difficult. So I had the flat repaired and leased it out. I am taking care of society dues, taxes and maintenance. The lease payments are made to my account. My name is the first name on the ownership record. My brother in law is going to India in a couple of months and hinted he wanted a share of the lease and I refused (indirectly). He has threatened to evict the tenant and have the flat sealed and "...let it go to dust" for all he cares since he is well off and does not mind losing the property but wants to make it difficult for me. I have 2 questions... 1. What can he rightfully do to change the current lease arrangement? 2. What can I do to prevent it? I have told him that I will try to make another trip to India in a couple of years and we can mutually agree to see the flat then. Would appreciate any advice.