Rented property issue

We stay in a house as tenant from almost last 30 years (independent house and not connected with landlord house). The property was given us on rent on just oral conversation and no agreement made for this ever. We always heard that this property is not legally owned by the landlord, however we never tried to explore much about it. 2 years back the landlord died and his son (the only member left in the family) has became landlord. But since then he is not issuing any rent receipt (we use to get from his father) by giving reason that he is not yet the legal owner of the property and mutation process is going on, hence he cant issue any rent receipt. Even he said if we want we can stop giving the rent. However, we have never skipped or stopped rent for a single month in last 30 years. I heard that the son of the landlord is trying to sell his properties to property builder. I tried to discuss with him about his plan but he refused to say anything and said if I have any problem then i can stop the rent. Now my question is do I have any legal right to protect my interest? I am not looking to get the ownership of this property in any unlawful way. I even asked him to sell the house to me but his father or he never agreed. In last 30 years we did all the renovations at our expenses. my worry is can he sell the house without informing me and the new owner (property builder) can just ask me to vacate the property ?