Placed flower pots on the joint property without my permission.

The joint property is an undivided Hindu property, in the name of my deceased father and my uncle. My uncle has a room of around 350sq ft constructed on that property, which he has access to only and i have a small 50sqft godown which i have access to only. But there is remaining 400sq ft of empty plot where he had filled it up with big flower pots around 50 pots without asking my permission. After keeping all this flower pots im unable to access my godown, and nor he can access his room(but he has no problems with it). Also the empty plot where he kept the pots is adjacent to my stairway of my house. It doesn't look good and during monsoon i have seen snakes there. I feel very unsafe most of the times.