Tenant false accusations

Hello sir I'm Ramu (26 yrs old) i live in vijayawada in andhra pradesh with my grand mother (70yr) she is seriously ill cuz she has undergone 2 major nuerological surgeries in the year 2013. My grand mother in the year 2003 has given a shop for tenant@300/- with 1000/- good will amount as she is the owner of the said property. After 4 years she asked 6000/- as good will amount which was given by the tenant and as the years passed by she increased rent gradually and by the year 2013 January rent was 6000/- only and she didn't increase good will amount of 6000/-.But in the year 2014 august 1st she asked the tenants to vacate the shop to hand over shop for me so that i can use it for which he didnt respond good and asked 5yr to vacate. so in aug 2014 we met police and explained our problem then they transferred our case to plcp there they called the tenant and us and gave him 1 year 4 months i;e by dec 2015 they should vacate for which he agreed and signed in front of police officials and the matter was settled. note-- a copy of that document is with me in which my tenant signed including my grand mother and mine and all the other police officials signs present there on that day were in that document as a proof. but shockingly in the month of nov 2015( after 1yr 2months) he send a legal notice from court stating that me and my grand mother tried to evict him forcibly using goondas and asked more rent and he also said that in the march 2005 he has given my grand mother 3lakhs as goodwill which is a false accusation. sir kindly suggest me what to do and there is no rent agreement written btw my grand mother and tenant since the last 3yrs and we dont have previous copy of agreements tooo