Tenancy right of married daughter to fathers rental shop where both father & land lord expired

I am a 40 year female, married daughter. My father was running a grocery business in Goa in a rental premise. The land lord & my father had an legal lease agreement of the same which was renewed for every 3 years. The rent was paid without any delays & disputes. There was no dispute of any kind between my father & the landlord. As the land lord moved from the state to another country, the lease was not renewed for many years but rent was paid regularly to the representative of the land lord who would visit on monthly basis. The land lord would visit the state once in 2 or 3 years as he was busy in his own work in the foreign country but never demanded to vacate the shop as he was in good terms with my father & due to his hasty visits the renewal of lease agreement (every 3 years) remained stagnant for many such years. My father thus continued the business for almost 15 years, out of which the first 6 years were regularized under the lease agreement & remaining 9 years remained without proper lease agreement as both my father & land lord probably because of good relationship Or time not permitted could not renew the agreement. There was no delay or dispute regarding rent payment. After almost 15 years, my father decided to close the grocery business & start the ready made garments business at the same place. The land lord who once visited the shop did not object to the business & allowed my father to continue with the new business. The renewal of lease agreement but remained pending because neither party had any dispute & it was a mutual understanding type of relationship between my father & the land lord. As time passed the land lord expired & after that my father also expired. After my fathers death my mother continued with the business & since I do not have a brother I started helping my mother in her business. Till now we had never bothered to check the documents related to my fathers business. We then checked the legal documents of the rented shop & came to know about the lease agreement (not renewed) & other licenses which were pending for long time. Now the legal heir of the land lord is threatening to bring legal evacuation notice against my mother. Can she be protected under the law from being stopped for running the business?