How to handle forgery case

I have issued one open cheque almost 4 years before to one person for security for the loan amount of Rs.30000/ which took that time. I have paid one half year 10% monthly interest for that person. Due to some problem i could not pay interest and lnformed him that i could not pay interest ,but i could settle the principle amount of 30000/- instalment . In the last year May 2014 i was to vacate my house since that person was having a shop in the same aparmnet where i had stayed. Before vacating the place i have paid 10000 by cash to him with 2 post dated cheque for 2 months for 10000 each, but that person did not deposit the 2 cheque and he utilized my one open cheque of HDFC which i gave him in the year 2010 . He has misused my open cheque and filled the amount of Rs.100000/- and sent for CTS collection in the month of January 2015. Since i did not have the balance in my hdfc bank it got returned. I immediately informed the bankers to stop the payment,since it was cts collection it went back . That person no issued a legal notice to me through his lawer as if i borrowed 1 lac from him . Now what i have to do against that person. I need your advice