Rental agreement

Hello Sir, I took a office on rental agreement with Rs 32000/month in Feb 2014 with agreement valid till Jan 2017 with 3 month notice from either side when we need to leave the premises. But Owner changed the rent from Jan 2015 to 35000/month without any change in the agreement. As we invested some money in the interiors of the office so we were forced to do so and he took advantage of it. Later in Nov 2015 he wanted to increase the rent to 45000/- then we told him that we can't do so and either abide by our older agreement or lets leave. Then on Nov 11, 2015 he agreed by the following sending the e-mail as: ******************************************** ( owner's e-mail) 1) It is not clear from your letter that whether you are vacating the premises from 1-1-2016. If you mention properly that you are terminating the agreement from today & will be handing over the vacant position in good condition from 1-1-2016, then I can start search a new party by giving ad in newspaper. 2) I don’t want to put more conditions like 3 months prior notice to you, because of losses you are getting to run your business. In case if you want to vacate with 1 month notice also not a big issue for me. 3) If you wish to continue upto the end of Dec-15, you can do it with reduced rent & mb, Please you can give any amount as rent, & you need not pay any amount as MB, because I am not able to mainten building as per your satisfaction. 4) From April-2016 I want to apply strictly our agreement dated 10-5-2012 (i.e., 45K rent, 100% MB, 5% escalation etc). Till that time you can give any amount as rent, but from your side if you want to leave early, you can vacate any time you want atleast by giving me minimum 1 month prior notice. 5) Reply me your correct decision at the earliest in order to search a new party from my side. ****************E-mail ends*********************** Then we mutually agreed to leave and informed him by December 2015 over phone and on Nov23, 2015 by e-mail. I looked at another small place and paid the advance at that place to start my office from January 01, 2016. But then he started saying that now I do not agree and you need to give 3 months advance. Then I told NO and in that case will continue with my 2014 agreement with Rs 32000/rental. Forced with this he sent me a 3 month notice to vacate by e-mail. Today he also sent me some lawyer's notice as well to my office and that I need to see tomorrow. Now what I would like to know- 1. Is owners e-mail is legally binding on him? 2. Can we adjust the money he has taken extra ( Rs 32000 agreement but charged 35000) 3. He charged maintenance but never gave bills or showed us even we asked ( common area electricity, water and Security personal payments etc). Can we now ask him the bills towards whatever maintenance he has charged during last 2 years or so. Look forward to your kind reply/suggestions. Thank you Rajeev