Occupying and capturing the government land (road) to blackmail

Respected Sir, With all due respect I beg to say that my ancestors had purchased two different pieces of land almost adjacent to each other by the registered sale deed from the then landlord in 1926 & 1929 and now my land is surrounded by the government land (ghairmazrua khas) and we have been enjoying the land (by cultivation) since my ancestors came in possession from the very date of purchasing the land. There are two govt.roads to reach my land but on both sides two different persons have encroached the road illegally with an aim of blackmailing me to sale the land to them what should I do. One of them has also built a small toilet type construction on the road (totally illegal as he has no any authority at all to capture the land) to make an obstruction and he demand Rs. 200000/- to me to clear the road. I am very confused and helpless what to do for the clearance of both roads and also want to know if I demolish the illegal construction myself will it would be treated as a criminal offense. Kindly guide me. I will be grateful to you for this guidance.