My grandfather has done a gift deed of his 50% share of immovable property and it is registered with registrar's office and stamp duty is paid in 2022. The gift deed is with me and I have not yet submitted the gift deed to society for the transfer of the flat in my name. The property is in Mumbai. I am currently staying in Bangalore and i am planning to submit the registered gift deed to the society in the coming 6 to 8 months. My query is, if my grandfather(doner) pass away before i submit(give) gift deed to the society will the gift deed stands valid? Can someone challenge it in court?