Transfer of title of House

Hello Sir/Madam, Sub: I live in Karnataka and the query is related to a house that I live at Karnataka. I have been brought up by my maternal aunt(Mother's elder sister) since I was 3.5 years old. Now I am 35 years old. I am not adopted legally by my aunt and nor intend to do so in future. My Uncle(Aunt's husband) is no more and I have done all the cremation formalities 10 years ago as they do not have any children. Eversince she is staying with me. She is now ~63 years old and would want to transfer the house where I grew up in name which is currently in her name. With my limited knowledge, I understand that gift deed is not possible and the likely option is sale deed. But I would want to avoid this because this not an actual sale and this is the same house where I grew up and do not want end up paying . My aunt now wants to transfer the house in my name and avoid any complications by making a Will. Kindly suggest a suitable option to get the title of this house tranferred in my name without getting into sale deed.