Harassment by daughter in law for property towards mother in law

My Grandmother has been living with us from last 25 years and my mother who is the daughter of my grandmother and my father and me anf my brother are taking care of my grandmother . She has been bedridden from last 4 years and everything has to be done by my parrents as my grandmother cannt move . the issue here is that my grand father had a property which he made by his hard earned money in his and my grand mothers name . After my grandfather diedmy granny is the sole owner of the property. she has made a will were she has named her share in the property on my mothers name as a way of love and for taking care of her since 1990 . now the eldest daughter in law and son have filed a false temperory injunction order agaisnt my mother saying my mom is trying to sell property. Im really fed up of their dramas every day she sends people to that property (were its been rented and the money (3000)that we get as rent goes for my grannys medicines ) to threaten the tenants to vaccate and has sent legal notice for share in the property.this daughter in law and other 2 sons jus visit her once in a while and have never taken care of her or the property . but now they want share in the property . Please advice as to what can be done on behalf of my granny and mother against these harassment and legal issues as my mother cannot run behind the leagal things as she is 63 years old my father 69 and my granny 82 yrs old and my brother who is in chennai has to take leave and travel to calicut kerala to be them for all these matters can my granny apply for permanent injuction against her sons and daughter in law and what else can be done for a relief from all these issues and troubbles fir my parents brother and granny thanks in advance sk