Property transfer

Hi , I stay with my Aunt (father's sister) and uncle from my childhood as the have no children. My uncle owns a house in hyderabad and he gifted it on to my Aunt's name, as she wants to transfer it on my name , even my uncle is also ready to do it but recently we have came to know that he( my uncle ) married other lady ( illegally) few years back and she have 2 kids now , my question is what is the rite process to transfer that house on to my name ( sale deed ,gift deed , will deed? ) I heard that sale deed will be good choice but will I be questioned how did I buy that property without funds transfer ? Please suggest me a good option to transfer that house onto my name without any complications. Thanks