Tenancy Right

Sir I have one small shop in Mumbai under pagdi System under the name of my father (my uncle who has adopted me) I was verbally adopted by elder brother of my biological father and I have aadhaar card, election card, ration card, school documents that shows my uncle's name as my father. My uncle had no child and I have been staying with him since I was 4 years old. I have no documents that show my biological father's name as my father. The landlord has been demanding 1000% increased rent and I paid him couple of years rent in one cheque from my account. The landlord sent a typed receipt in my father's name ( My uncle who adopted me) on WhatsApp. Couple of years rent is pending as per his increased rent for which he is demanding single cheque When I sent around 2 years rent as per his calculation ( a part of pending rent ) along with death certificate of parents who adopted me he refused to accept the cheque mentioning that I am not son of the tenant and asking me to vacate the shop The shop is my only source of earning. Due to health issue I am not working daily on shop but I do work once a week. I have a person who works in my shop to manage the work load. Please advise me what should I do to prove my tenancy right