Legal Heirs

SIR My father -in- law had inherited the land property from his father through Dhana Settlement after his marriage.He built a house in a part of his land by pledging that part of land in a bank.Then, he transferred the house to his wife by Dhana settlement (2001). After a few years, he again built a house in the rest of land by his own money. Unfortunately, his wife died after ten years (2010).My Wife and Her brother are the two legal heirs of their parents.I got married my wife after the death of her mother (i.e) in 2011. In 2016, My father-in-law had transferred his property in the name his son through Dhana Settlement without any intimation to my wife. And,My father-in-law and his son are saying now that we will not provide any property / settlement from our side. My questions are, - When two legal heirs are alive, Will the registered Dhana Settlement Pathiram in the name of One Legal heir acceptable by law if my wife object it? - Who will be the responsible for loan obtained from the bank if the bank document says the legal heir of Mother - in -law is my wife ? - My father in law has one sister and she got married before 1989 itself. Has she the right to get the property? NOTE: I do not know whether the Dhana Settlement Pathiram received by my father-in-Law from his father is registered by legally or Not? Kindly guide me plz