Commission are brokerage

Section 44AD is generally applicable to buinesses (like retail, trading, etc.). Commission income might not directly fall under the typical businesses covered by Section 44AD unless the client is engaged in a business eligible for presumptive taxation. 

Filing ITR3 without books: If the client's income is from commission and not a business eligible for Section 44AD , they might need to maintain books of accounts or follow regular income computation methods.