Dear sir,
You need not worry about the passage area as it is illegal as long as you can prove that you have claim over that property. Law grants easement rights to property holders. In fact there is a whole legislation devoted to easement rights- the Indian Easements Act, 1882 wherein it is clearly mentioned that "An easement may be acquired by the owner of the immovable property for the beneficial enjoyment of which the right is created, or on his behalf, by any person in possession of the same."
You can approach the court for injunction under Specific Relief Act to restrain the disturbance of the easement.
Also, to register the property in your name, you will need the death certificate of your father, affidavit along with legal heirship certificate and other documents as required. It will be registered at the registrar's office of your residence. Thank you.