Eviction of House given on Rent

I have a person who have moved in my In Laws House. While moving in he had hidden the fact that he and his mother both are working and also told that only he and his mother stay in the house. So we allowed him to come and stay immediately on Humanitarian basis even without any agreement or any financial translations. After he moved in we came to know that not only he but his mother is also working and she is a government employee along with him his sister and her daughter also stay. So we requested him to pay the advance and a fixed monthly rental since both of them are working. Now he says that he will pay only 4, 000 Rs as rent which he was paying in his last rented premises. Our property is a huge 2 bedroom independent house more spacious than his last accommodation. Our previous tenant was paying 6,500 Rs. now this person is saying after moving in he will pay only 4,000 Rs. I have asked him to vacate and look else were. Its 20 days since he has moved on, He has not met us, nor moved out. what should we do