Cheating in the name of business partnership. How to proceed?

I am a currently working as a software employee in Hyderabad. I was looking to go into business field and was looking for a company to invest join as a partner. In that process I met Ravi Varma who runs a proprietorship firm named "Team3 Solutions" which is mainly a Graphic designing firm. He convinced me that he is forming a private limited company and offered me a share of 20% in it for an investment of 7.5 Lakhs. I paid 6 lakhs in full in the November 2014 and 2 lakhs more in the following 6 months as working capital (Total of 8 Lakhs). He showed me lot of business concepts and other business opportunities. In reality, he never did any work towards those business proposals. I realized that I have invested in a wrong person and so in the month of February 2016, I said I do not want any kind of partnership and asked him to give my money back. He agreed to the same and said he would pay me back in 3 or 4 months. It is more than an year now and I received only 2.5 lakhs out of 8 lakhs. Every time I ask money, he postpones it by showing some reason. I also did not want to push it much in the fear of losing my money. Today, he started to threaten me saying he will not give me anything and I can do whatever I want. I am sure he is guilty and needs to be punished for fraud case but not sure how to proceed legally. Can you please help me out. Please Note: I have bank statement showing the 6 lakhs transferred to his account and other expense details for the 2 lakhs used as working capital. I have agreement written on bond paper, which we made while getting into partnership with the required financial and partnership related details I also know another person who is the same situation as me and is suffering like me.