1. You have a two fold legal remedy against this person.
2. As per the agreement he was obligated to pay the balance amount within 4 months from the date of agreement, failing which you could present for encashment the cheque given by him. Since he has not fulfilled his promise you may file a suit for recovery against him in the court. The filing of the suit may be preceded by issuing a lawyer's notice to him, but this is not mandatory.
3. If the cheque issued by him and presented by you to the bank has been dishonoured then you may file a criminal case for cheque bounce against him. It carries an imprisonment of up to 2 years. The legal process to file a criminal case has to begin by necessarily issuing a notice trough your lawyer to him demanding the payment of the balance amount. If he does not pay even after the notice then you may go ahead and file the criminal case against him in the court.
4. Both the cases can be filed simultaneously.