Eviction of Tenant

Hello sir/Madam I am a landlord and given my flat on rent in sep14 in Delhi. Tenant paid the rent for 4-5 month after that he refuse to pay the rent & asking for 2lack rupees to vacate the premises & saying that he is paying the rent continuously since he was paying it cash , I do not have any proof for rent . He is also doing some illegal activities (prostitution) as we got to know form neighborhood , but nobody is ready to give any written statement. We are in a lease agreement for 11 months which is already over now . I sent him 2 notices which was undelivered & returned back to me . Kindly suggest how to proceed The rent is 7000 . Will I be getting my arrears or how much time it take to vacate.