Tenant declines to pay rent as per Registered Lease deed

Commercial Prime Property in Noida leased for 5 years with 3 years lock in period as requested by the tenant with penalty clauses for both the parties if failed to follow it.Tenant after two years of occupation(having paid regularly), is vacating the premises with out paying the rent for the third year (lock in period) @ Rs.1,31,700/-PM( Totaling to Rs.1580000/-for the 3rd year) as agreed to in Para 13 of the Registered Lease agreement.as under:- Para 13.That the lessee has requested for 3 years lock in period for the above said premises with effect from 01.04.2013 to 31.03.2016,during which he shall not vacate the premises as long as he is abiding by the terms and conditions laid out in this lease agreement.However in case of any reason if the lessee vacates the premises earlier then 3 years he will pay rent and connected charges for the complete 3 years duration.However,the lesser shall be required to pay double the amount of security deposits that is Rs 11,50,000/- to the lessee if he wants the premises to be vacated before the lock in period,as per mutual consent of both parties involved in this deed.The lessee shall hand over post dated cheques in advance for the lock in period before 30th April 2013 as mutually agreed.The Lessee shall hand over the cheques for the remaining period of the lease before 28th Feb 2016. Request advice:- 1.Can a verbal conversation ( recorded on mobile by some unscrupulous person ) on the reduction of rent be quoted in the court and nullify the Terms and condition of the Registered Rent Agreement 2, Can I recover the rent of the lock in period that is 3rd Year if the Tenant vacates the premises after 2 years (after adjusting his security deposits which are only refundable after adjusting the breakages / damages and the peaceful vacation of the premises). . 2. Shall I take over the possession when he vacates during july 15 as he has planned to adjust his security deposits instead of paying rent from April to July 15.