My mother- in-law had a 35 cents of landed porperty with one old 100 years old house, which was unfit to live due leaking during moonsoon and damaged with white ants etc, and none was living in it for 5 to 6n years. This was purchased by my father in law on my mother in laws name. Out of it 7 cents she fited to her third son with whom they were staying all along. Elder dauther was married and away since jan 1970, with occasional visit yearly or biyearly as per convenience. Elder son was also away since 1976 and staying there with parants. Other two daughters were with them but got married and gone separately. In 2008 since the old house was fully damaged unfit to live, she asked every children specially her third and yourgest daughter to repair the house which the father had purchased with his hard earned money. Allof them refused and advised her to sell the balance of the property ie 35-7 = 28 cents. My mother in law was not willing to sell the property. Finally she told me the elder daughters husband on my one visit ther about the entire story and her unwillingness to sell the balance property. After a well thought, I told her since all other childre refused to repair the house and wanted to sell it, but she does not want to do so, if she gives the house and it's sorounding to her and the balance equally to other children less her second son whom she had already gifted 7 cents, I will repair the house, even though I do not require a house there in Kerala. After her discussion with all children she executed a property settlement deed on [deleted], giving my wife ie her elder daughter the house and it's sorounding total 7 cents with the existing 3 meter width way to the house from the panchayat road and the balance she gifted to other three children 5 cents each. She did not take any property and we promised to look after her.But she refused to move with us and continued to stay with her second son whom she gifted 7 cents earlier. The deed was duley executed on [deleted] and the property handed over the concerned children. Since 2014 onwards she became a dementia patient and remembers nothing and knows any body. Now her second son threatned that he will get the settlement deed cancelled by taking her thumb impression even though she does not remember anything and not in good health brain nerves full weak or damage and no treatment She was 87 years old. Under such condition can my brother in law her second son 1. cancell the deed and settlement after 6 years? 2.Will the thumb impression taken when she is a dementia patient and not in good physycal and mental conditon be a fraud and illegal and against all ruls and laws of the land? 3. If he can do it, what will happen to the money I spend on behalf of my wife her elder daughter for the renovation of the house and re-construction of it during the past 6 years?.