Itr

This is an income other than regular salary income.  In my opinion, you must consult your auditor who will take care of the said requirement.

Received commission is an income under the head 'INCOME FROM OTHER SOURCES"  and added into the total income.

This income falls in the category of the head "Income from business and profession".  If your gross commission during the FY is not exceeds 1 crore.  You can file return in the form "ITR-4S" by taking profit @ 8% of the gross receipt.  Otherwise if you get your account audit by CA , you have to file your return of income in the form "ITR-4".