Tenancy of sole proprietor post his death - right of heir on tenancy

My father and his brother used to run a retail store since 1990s in a leased property. They signed an agreement with the landlord (a trust) in 1993. In the agreement they named both brothers as proprietors of the firm M/s ABC. The rent receipts were issued in the name of M/s ABC - and names of two brothers till 2000. From 2001 - the rent receipt was issued in the name of M/s ABC and my father as proprietor. This continued till 2013 In 2014- the receipt changed to M/S ABC only. In 2014 my father suffered a heart attack. Post that till date they are issuing the rent receipts in name of M/s ABC. In 2015 - my uncle passed away- my father continued to run the firm. My cousin (uncle s son) continued to work with my father. My father filed income tax of M/S ABC in his PAN 2015. In 2018 my father passed away .in this year my mother paid rent with cheque from the firms Bank Account along with application to issue rent receipt in M/s ABC and her name. The LL is insisting on only M/s ABC.