Got legal Notice By lawyer

Good Morning sir/ Mam, I am a Civil engineer; previously I was working as a civil contractor in a real estate company. I was in touch with a person through one of our mutual female friend, once I was in need of some money, that time my female friend asked that person to help me and he deposited the sum of Rs. 15000.00 + Rs. 10000.00 in my account. After some time he asked me for money return and then I deposited the sum of Rs. 19000.00 only in his account. (Now I don’t know the account no.), after a period he started claiming 10% compound interest on his 25000. and forced me to pay Rs. 87000 more. I was in a big trouble. His female friend also told me to pay the money with interest. Then after I issued two different dated cheque of amount Rs 50000 and 37000 of my business bank (Current account of my construction firm.) I told him when I will ask you to deposit the cheque then after you present the cheque in bank, but he did not listen to me and deposited those cheques and they ware bounced 10 month before. This matter happened A Year before and those cheques has no credibility. There is nothing between us in writing. Now he is making false allegations that he gave the sum of Rs 350000.00 (25000 deposited in account and rest in cash) and I ware promised him for flat (property). He sent me a Legal notice and asking for make the payment otherwise he will go to court and file suits U/S 1860. I am going denial of all allegations makes by him through a lawyer, my question about the cheques, what reasons I should have to put for issued cheques. is it be Good if i say that i ware issued post dated cheques for the supply of materials, neither he supplied the materials nor i made payments ? Please guide me that how to respond Please reply as soon as possible. Thanks and regards Atul kumar Email- atul.technocivil@gmail.com