My father before dying made a will giving the apartment in whihch he stayed to me. I have an elder sister who eloped and married someone from a different caste, therefore my father gave her some of his money which was in FD. The will has been probated. Even the nomination form in the society has 100% share in my name. My husband as a gesture of good will wants to give our own house to my sister since he feels that the value of property given to us is far higher. We have put our house (my husband's) on rent and from day 1 the rent is credited into the account of my sister. Now my sister's son is threatening us that unless we sell our property and give his mother the proceeds, he will file a claim against the house given by my father to me. Is he within his legal rights to do so?