Vacating the owner of my neighbouring flat from my flat

I own a flat in Bhopal. I was employed in a nationalized bank in South India. Owner of my neighbouring flat contacted me through phone and wanted to occupy my flat for few months to renovate/repair his flat. I agreed and allowed him on payment of rent, electricity, water charges and society charges for few months, asking him to deposit the rent in my account. No rent agreement was made as it was meant for few months by the owner of my neighbouring flat. The fellow gave his flat on rent and continue to occupy my flat. His used to pay rent for two three months together, but no issue. Now I am retired and I want my flat for occupation. The fellow is not vacating on various pretexts, and I am staying with my mother in law. Another embarrassment. I am a law abiding citizen, and do not want to indulge in any illegal means. I have given him four months notice on 10.08.2018 to vacate my property or face lagal action. Also mentioned that I will sue for recovery of my legal expenses. Pl advise me.