Breach of trust by Licensee

Hi, This is in reference to a shop owned by my grandfather who is 80 years old. We have had a tenant in this shop for more than 10 years now, last month the L&L agreement expired, tenant met us and we decided to renew the terms of the LLA wherein the rent amount was revised and it was decided to have a 11 month LLA post which we will meet again to decide the continuation of the LLA. The tenant prepared the new LLA and we were okay with that as we had trust in them as it was a long term relation we had with them. During the Registration day my grandfather along with my uncle visited the Registrars office, while my uncle was parking the car, my grandfather was accompanied by the tenant and his Registration agent into the office. There they finding my grandfather alone with them they presented him the LLA and asked him to sign the document, as we had trust in them we noticed only the clauses which mentioned the rent amount and some basic corrections which we had discussed with the tenant and my grandfather went ahead with signing the document. The document eventually got registered. After this my family was following up with the tenant to share the LLA registered copy for which he kept delaying and making excused that he had lost the copy. After 5 days of follow up and no results, we managed to get the notarised copy of the LLA from the Registrars office, to our surprise we found that all clauses were modified and the whole agreement was changed favoring the tenant. Terms like tenure said 60 months instead of 11 months, where there was no lockin decided the LLA had a clause of 60 months lockin, fixed rental amount for the whole of 60 months, Licensor having no rights to terminate or modify the LLA. It turned out to be a complete breach of trust and the tenant finding the LLA favoring completely him and being registered is giving no heed to my families concern. He is not willing to cancel this LLA and do a new LLA as per discussed terms. My grandfather is in lot of stress, he is a heart patient and its his hard earned lifetime property, please need assistance in handling this situation. Your advice will be of great help!!! Thanks. Shakti Singh E:[deleted]