Fraud case Online Cheating Help

Hi Sir  I am an NRI and a person in Bangalore have seen my rental flat add and have contacted me first to help me get my flat rented however I denied then he told me if I can invest 1 lac in rental business just as an investor he will pay 3000 per month as return and my 1 lac I can take back any time. He sent me a draft contract on email as I stay out of India, then I transferred him 1 lack online for which he acknowledged over the email also. Later he was not paying me 3000 per month and only paid for 2 months after which he have blocked all my numbers and recently I got his number somehow and threatened him that I will file a cyber fraud case as the email marketing trap he have done with me and then he agreed to pay me 5000 per month from Aug 14 to Dec 14 in 2020 and from Jan he will pay me 10,000 each month until my money is cleared. He again paid me in Aug Sep and Oct and from Nov he started the drama and excuses again and delaying my money taken in March 2019. I just want him to send a legal notice first and if he is still not agreeing to pay back my remaining 79,000 please guide me what I should do next as I am a NRI and cannot go to local police station in Bangalore and he is taking advantage of this situation of mine. But I am sure he have cheated many people like me, cheating is his profession please help me to teach him lesson at least for humanity sake any money earned by anyone with honesty is very difficult and people like him are cheating and taking away hard earned money. Please help me. Thanks Raj