Dispute on parental property for a small portion of old construction

My Grand father has distributed the land among 4 nos son in 90's.But the whole land was not distributed in equal manner.Two Uncle had taken free land in that premises where as my father & uncle kept Two room each in old constructed building along with some free area.My Father had constructed the house & remodeled the old two room 20 years ago.If we see the plot -partition document ,small portion about 60 sqf is showing in my uncle portion.it was done Based on mutual understanding basis at that time because of old constructed Two room's few portion coming into it.Now after 20 years My uncle raised this issue & damaged our treas area.He is claiming that it should be in his portion. Now he is calming some free portion of basement near to entrance gate.Apart from that he has encouraged govt.land from front side & right side of his house in a illegal way & constructing 4 stored building on top of that. What kind of Precaution measure i can take to avoid further damage to my building?