Want My Money Back From My Frnd

I have given 1 lakh rupee to one of my frnd through net banking 1year ago and he has promised me that he will use it in bzness and will give me 2 lakh but till now he has returned only 50000 and now  he is not returning remaining amount.since I have only passbook print as proof So can I file civil suit against him just on d basis of my bank pasbok entry or not . U can say he is running chit fund cmpny becoz he is taking money from people and promising them that he will double it in a year and he is jst circulating money between the people by taking money from them and returning their own money in installment by telling that it is their interest. Now when I m asking to give back my remaining 50000 then he is threatening by saying that giving money to sumone to get more interest is also illegal so if u will fill case against me you also will be in trouble.now what should I do to get back my atleast remaining principle amount.