Tenant not in India and agreement expired, how can family vacate?

I am happy to see this site today. My sister's family is in Bangalore and their lease agreement had been made on my Brother-in-law's name in Dec 2012. The agreement was for 11 months and it got expired after that. No renewal was done after the expiration. Lessor had increased the rent amount twice so far and the family is paying rent regularly (Lessor has been giving receipts every month till now). My brother-in-law has moved out of India in September 2015. Their family size has grown in size with children and due to that they are in need to shift to a bigger house. When my sister spoke to the Lessor, he told they cannot vacate the house now and he said my brother-in-law should sign in a document and the landlord issues some 'vacation certificate'. When my brother-in-law spoke, the Lessor said they need to give 3 months of notice (not mentioned in agreement), after which he is expecting my brother-in-law to come and sign in the documents to vacate the house. I'm not sure if there is such thing called a vacation certificate. My brother-in-law cannot afford the travel expenses to come to India only for signing the document. Please advise how to proceed further.