Are the titiles of our flat clear

Respected Lawyers, I am really frustrated with hearing different things from different lawyers and not getting a clarity. Here is my case My father and his elder brother (my uncle) purchased a flat jointly, later on my father paid my uncle (who has passed away now) his share and a family settlement was done and my uncle released his rights on the flat, this was notarized with a lawyer but not registered. Later on my father passed away and my mother was 100% nominee. I applied to the society to transfer flat to my father and they asked me to see a society lawyer. He told me that the title was not clear since the release deed between my uncle and dad was not registered and has no value. I was made a file for a letter of administration on my mothers name where my brothers and sisters (we) released our right to the flat to my mother and gave NOC. Later a letter of administration was got from court and the share certificate is on her name now. Another lawyer told me I have to get NOC and release deed from my uncles daughters and his wife and then when amnesty scheme comes I have to pay stamp duty and registration on the flat to clear the title. One more lawyer said that once the share certificate has been transferred the title is clear and my mother is now the complete undisputable owner of the flat. My questions below 1) Is the file title clear now? 2) If this flat has to be sold can it be sold or is it that title is not clear and hence cannot be sold. 3) If my mother wants to make a gift deed of the flat to me is it possible and what all is needed with this situation and documents we have.