Blank cheque and blank note given to one person

Sir my age is 25 in the year 2016 I thought of buying a second hand car and I saw a car in olx site and consulted that person and he said the car is in other city so I went there and then he said he will be selling it for 2.9 lakh, I said I have only 2 lakh he took me to his home and he and his family were became very friendly and he said he can provide a friendly loan for remaining 90k as my parents liked the car I said I'm a small employee working on contract basis and I have never taken any loan by hearing this he said to me see you are looking very good boy want to make your parents happy I'll help you don't worry so I trusted as seeing their family and he asked a cheque and asked to only sign on it and asked sign on blank registered stamp paper he said this is mandatory and your security purpose and return after my email payment completes I stupidly agreed and he handed me the vehicle and duplicate RC book and said he will give all the documents in a week and asked me to take the vehicle after 4 days he can to our house and said his son wants to study at my place and he knows no one their asked me for help to take of his son and he stayed at my home after that day when I use to ask the papers he used to say I'm little busy it's my duty to give papers wait trust me my son is also with you where I'll go.i have paid 2 emi's and asked them he said he will provide papers when I complete all emi's I have seen 2 months and said you please get all the papers I'll clear all the amount then he said you first give the money I'll get then I said no you get the papers I'll give money then hand over the papers to me he kept silence for a few days after his son left our house without intimating and he sent some persons stating that they are financer of the vehicle and person who sold the vehicle have taken hand loan on the vehicle and not paying any emi and they wanted to recover the vehicle they asked me to pay 1.2lakhs but I need to pay only 70k and paid to them 15k to stop them to not to take vehicle and taken the receipt I called the person who has sold me the vehicle and said I'll pay total 1lakh amount you please give me all my papers then he started back mailing me that he needs 4lakh for that blank cheque and note and 1.5 lakh for the vehicle after listening this I totally scared and intimated my parents and given stop payment instructions to bank and my father lodged cheating case against him in the month of feb2017 after police have called him then in the month of april without coming to police station he dishonoured my cheque in their Cities Bank and sent me a lawyer notice as I was not residing with me parents due to my job I'm unable to take now this month December 2017 I got summons to attend court on 12dec I received on 12th so next hearing is 18th Jan 2018. I'm scared I already consulted a lawyer he asked me some time so please advice me sir how to defend the money is huge I can't pay. I have F.I.R,olx add copy and vehicle.