My mother own a house in Delhi and in the year 1997, by way of registered will she transfer her ownership rights in my name by way of Registereed will at Delhi and to that my father has witnessed. My parent has three sons and three daughters. We have doubt that only one brother may object and / or challenge to this. Both my father and mother aged 86 & 82 are alive. Please guide - is the registered will is challangeable and / or what to do at this point of time when my parents are alive. One more point - Relinguish Deed is executed only after death of a person or during his alive, one can executed. What are main points of difference in Relinguish Deed and Will.