Can i regularise a building plan which is in the name of my father who is dead now?

-my father is dead and the said property is still undivided.i am having two sisters alive and married.my mother is also deadYou cannot take an action on a property which is not in ur name. First ascertain if there was a will and the contents and take action according to that. Get the title of the property settled before any action can be initiated. Consult an advocate, (may be more than one to get better idea), and follow the legal advice.
Consult a Good Lawyer, obtain Probate from the Court as Hair/Administrator and Power of Attorney from other members of your family members for the matter. Things are difficult if you have cordial relations with your family.