Income

He should file his return in ITR 4.

Her income from commission would be considered as business income.  So all the expenditure incurred by her in connections wiht her business receipts would be deductible from her income for calculating the tax liability.  Also if her total commission income during the F.Y. exceeds Rs 1crore then she would be liable for tax audit and will ahve to maintain the requried books of accounts & get them audited from a CA before filing her return of income.

In adition to the expendituer incurred for business, she would also be eligible for teh deductions under Chapter VI-A i.e. deduction u/s 80C, 80D, 80G etc...