You should make a police complain as soon as possible. Under the Indian Penal Code, 1860, any unlawful entry into property in the possession of another with an intent to insult, annoy or intimidate another person is a criminal offence. You are legally in possession even though you may not physically occupy the plot. At the same time, a suit should be filed against the persons involved against such trespass. This will not easily yield a remedy but is important for the maintenance of your legal rights. In such suit, you should also ask for a declaration that the property belongs to your father and not any other person. The reason for this suggestion is that the land mafia then cannot legally transfer the property without your rights being considered. Also, it may be helpful to file a caveat in the court i.e. a document that requires the court to give you a notice in case there is any suit filed in relation to this property so that if any person tries to deal with the land and there is any kind of litigation, you can join in and agitate your rights. Although under the law, you have the right to use reasonable force to eject the trespassers, I don't think while dealing with the land mafia this is a feasible or realistic option. Section 52 of the Transfer of Property Act, 1882 provides: During the pendency in any court having authority within the limits of India excluding the State of Jammu and Kashmir] Government or established beyond such limits by the Central Government of any suit or proceedings which is not collusive and in which any right to immovable property is directly and specifically in question, theproperty cannot be transferred or otherwise dealt with by any party to the suit or proceeding so as to affect the rights of any other party thereto under any decree or order which may be made therein, except under the authority of the court and on such terms as it may impose.