Urgent - need advice on how deal legally against ex-tenant

Hi, I am currently travelling in USA & not available in Bangalore. I have a flat in Bangalore. I had finalized a tenant 3-4 months back with certain mutual demand. He had paid 1 Lac INR as deposit & 20 K as rent per month & we had done the notarized rental agreement (with 1 month mandatory notice to served if vacating flat). I made all arrangement for him stay in my flat with a particular date actually & the same date was also mentioned as move in date in agreement as well. This guy did not move in in mentioned date & started giving all possible irrelevant reason of mine not delivering as committed & keep demanding all new stuff which I also did. But after 20 days post move in date & said that he wanted to cancel lease. I told me give me 30 days notice & I will refund 80 K INR by deducting 20 K i.e 1 month notice. I have already paid him back 80 K online. Still he is writing threatening emails & threatening that he will take legal action against me & also the new tenant if he does gets back complete 1 Lac deposit back. I tried discussing many times that why he expects all of 1 lac but no use. He is making my life horrible & not ready for any settlements. I am ok to pay him some more many & but never really want to pay back all, because I have many effort financially, physically to meet all possible demand & also he is supposed to give me 1 month notice for 20 K one month rent deduction is reasonable. Is there a way I can deal it legally before he does something dangerous or may be legal action without my presence in bangalore ? Who hold genuine stand legally ? What way he can impact me legally ? Need Urgent Advice. Thanks