Money cheating by a family member.

My mother's nephew had borrowed Rs. 7 lakhs from my mother a year back promising that he will return return the money in three months. He had done the same to two other ladies in my family including my mother's sister who are of my mother's age. When they asked to return the money, he asked for extended time a few times. When they asked for the money again, he filed a case in a local police station against my mom and her sister stating that they are harassing him for money and his life is in danger. The police called my mother's sister because she resides nearby and sought information. There he made an agreement to pay back the money in a month and the police officer supported this. But on the scheduled date he came with just Rs 40,000 and the police officer told my aunt to buy it and go, as they can't do anything else. It seems like he had bribed the officer. In fact,one of the policemen also asked my aunt for a proportion of the money, but she refused to give it. What should we do now? He had given all the lenders a cheque and a blank promissory note with his sign. He works in a Panchayat office in Kerala. Should we see an advocate, file a case or see the district collector as he works directly under the collector's department. Will we get the money back? Will it take much time, because we are in quick need of money for my higher studies.