Including mother’s name in society share certificate after the death of my father

My parents jointly owned a flat in Andheri, Mumbai (50% shareholders). Father passed away suddenly and unexpectedly in Coimbatore, Tamil Nadu, in October 2021. As he had resided in Coimbatore for more than six months before his death (during Covid lockdown etc), and as parents also own an apartment here, we managed to get legal heir certificate from Tamil Nadu state. Father died intestate, but had made me the nominee in Mumbai as well as Coimbatore. When we went to Mumbai to process the Share certificate, we were shocked that the society squarely rejected the Tamil Nadu legal heir certificate. We were asked to apply for ‘Letters of Administration’ At Bombay High Court, which we did. After almost 11 months, we got the LoA in January 2024, clearly stating that our mother has all the rights to administer the property in Mumbai. The society is still harassing us procedurally by slapping many other documents, affidavits etc. & dragging on the process. The lawyer who helped us get the LoA says all this is unnecessary when there is a clear court pronouncement, but he does not want us to go on the offensive. He just wants us to cooperate with their demands and somehow get the share certificate from them. Do we have any legal options here? Isn’t the society misusing its powers and harassing an old lady of her right to her property?