ITR4 and ITR4s

“The term ‘turnover’ for the purposes of tax returns may be interpreted to mean the aggregate amount for which sales are effected or services rendered by an enterprises”

In your case if you only received 10,000 as commission for rendering any services then it is the turnover as well as your income since you have not incurred any expenses.

But if you have received the full transaction amount based on which you are entitled to get commission then the transaction amount will be your turnover. Suppose your commission is 10% on any transaction (it depends upon the nature of commission you've recd.) then your turnover is 1,00,000 and 10,000 is your income on which 1000 has been deducted as TDS. Generally this is the case of consignment agent who sells the goods of consigner, recovered the full amount and after deducting commission balance money remitted to the consigner.

As far as the ITR is concerned you can fill ITR-4s. Don't get confused with Presumptive income u/s 44AD which precisely means for Civil Construction. Person earning income on other than civil contracts can also use this section for the purpose of filling itr4s but clearly specifying the nature of business. Because it will be clear from the nature of business that it is for other than civil construction.