How to protect father's property from hostile son & ex-wife?

Hello all, A brief summary. - My father & mother have bought the current building where we reside. They are the landlords & had bought the building in 1979. - We own & occupy two flats in the building. In my parents will, they have given one flat to me and one to my brother. - The other 3 flats in the building are occupied by tenants (pagdi system). My parents have willed the building, common areas & joint landlordship to me & my brother (jointly). - Mom is alive, daddy has passed away. Now, I am divorced and happily married with my 2nd wife. Things are hostile with my 1st wife and my son (from 1st wife). My question = how do I protect my parent's property from my hostile son? Is the will enough? Am hearing contradictory things about wills, self-acquired property etc. so thought of coming here for advice. Can he make any sort of claim on my parent's property? If so, how to prevent that? Thank you!