Transfer of Ownership of Mumbai Flat to Legal Heir who are also Nominees

Hello, My Father had made me(Son), my sister and my brother as nominees in our flat in Borivali, Mumbai were we have been staying together for the last 25 years. My mother passed away in 2013 and my father passed away on 15 Jan 2017. Being the nominees and Legal Heirs, we applied for transfer of shares & interest in the flat to all 3 of us(me, sister, brother) by submitting the following: 1. Cover Letter - informing about the death of my father and informing about we being the sole legal heir + nominees and thus to transfer the ownership & shares and interest to us. 2. Copy of Accepted & Acknowledged Nomination Form having our names in it as proof. 3. Copy of Dad's death certificate 4. Appendix 18 (Indemnity Bond) - though not requires as all nominees were to be jointly added as members but still gave it as society legal advisor forced us to give. 5. Appendix 15 - Form for transfer of share & interest. 6. Copy of Share Certificate Thereafter after a lot of time, society in it Managing Committee meeting & AGM endorsed our 3 names into the Share Certificate + made entries into membership and other registers for the same. This will be around april-may 2017. Now in April 2019, suddenly the secretary told us that your transfer is invalid as you 3 are merely nominees and nominees are only trustees and not owners in property so your transfer is invalid and there is some court procedure + fees to be paid to get ownership. We explained to him about the fact that we are also sole legal heirs of our father as per Hindu Personal Law + Income Tax Act, etc and we had also provided indemnity bond to protect the society against any claims to our property. Now if Nominee & Legal Heir are the same set of people, how can we transfer the property to our selves? So the transfer that society had done in AGM is legally valid and it was as per procedure given by Society's legal expert and also vetted by him. But he is adamant and also said that incase you want to sell this property then he will not sign on the transfer forms. This attitude is creating a lot of issues and mental tension for us. Kindly guide us what should we do as MCS Act is not very clear on what is the procedure for transfer/transmission of flat incase Nominees & Legal Heir are the same. How can we sustain our right of ownership in our dad's flat legally. Awaiting your reply, Jiger.