Flat not vacated by tenants despite notice

I, handed over the keys of my flat on 21st Nov15 with a mutual consent that the tenant will take the responsibility of executing register agreement for which the expenses will be born equally by both the parties and it will be actioned immediately. All the required documents were handed over to them in the month of December itself. However post repeated follow up the agreement was yet not done. So discussed and agreed that the rent will be paid on first of every month for the current month however rent was deposited at end of month for the month of Jan'16. again when we met on 13th Feb 16, it was again agreed that agreement will be registered within a week by bearing equal expenses by both the parties. However the given word is not adhered and tenant refused to do agreement as well as refused to accept the cost of register agreement post 2.5 months. There was also request made to adjust the rent against deposit of 35000 ( deposited dated 31st Dec15) which was refused by me and it has been communicated to him. We also asked property agent to collect the documents from you on 17th February 2016 in the morning in order to execute the registration on 20th February 2016 however they refused to hand over the documents. we sought legal advice and sent him a notice however it was returned back thrice until the lawyer personally delivered we then wrote an application at police station and it was taken in writing from him that he will leave on 2nd may. however now he sent me a text stating a notice has been sent to me and has refused to hand over the keys even though society has seen him leave the house after shifting all his stuff. There is a lock and need advice on how to proceed further