Can my father transfer my mother property in his name without consent

My father and mother had bought a house in Mumbai in 1983 which is a co operative housing society and both are equal 50:50 owners in this property. We are 2 brothers and 2 sisters in the family. My mother died in 2011 and my father is still alive. Shockingly I came to know that recently my father has transferred the 50% share of my decease mother in his own name and then my father transferred 100% ownership of this property to my younger brother without taking any consent of the elder son and two daughters. I tried to explain the society that it is not appropriate that you transferred 50% share of my decease mother in my father's name and then transferring 100% ownership to my younger brother without offspring consent but they say that wife's property automatically gets transferred to husband and it is not necessary to take consent of the offsprings. Following are my queries : 1) If my mother has made no will then this act is right or wrong? 2) If my mother has made will in favor of