Person took money and promised to return now ignoring

Hello, A person close to my father convinced him into investing in a TV show by making a payment of Rs. 3.5 lakhs. My father put his trust on the said person and gave him the money. My father was supposed to get Rs. 6 lakhs to be paid in monthly payments of Rs. 1 lakh each two months from the date of his investment. The said person had given my father 6 signed post dated cheques of Rs. 1 lakhs each. And my father being a simple man and having trust on the person did not sign the deal on a court paper. Instead the deal was written and signed on a simple piece of paper. I live in another city and so did not have any knowledge of this transaction till it was too late. Later on, the said person could not keep up his commitment and he has been postponing payment since last 6-7 months. What are the legal actions that we can take to recover the money? Thanks.