Can lifelong tenancy protect senior citizen from eviction in Mumbai?

My mother has been living in a Pagdi apartment in Mumbai for over 50 years. Recently, the court issued a small ruling requiring her to vacate the apartment within two months. The case has been ongoing for nearly 40 years. During my late father-in-law’s lifetime, there was an agreement that the landlord would sell the apartment for ₹28,000. My father managed to pay 65% of the amount but could not pay the full sum. However, as per the agreement, he was allowed to continue staying in the apartment. The current petitioner, claiming to be the landlord, asserts that the previous owner sold the property to him, though he has failed to produce the original sale agreement. We are now in the process of filing an appeal. My question is, under the law, does my 85-year-old mother have any right or entitlement to this property, considering her long-term residence and the earlier agreement?