Person receiving commission and also doing retail sales, can he take benefit of composition scheme?

Person registered in gst under regular scheme is doing Spare parts sale business with T/o of Rs. 20L P.A.. He's also in receipt of commission of Rs. 5L P.A on doing vehicle sales from Vehicle Company.

As his product category mostly comes under 18% GST, he's willing to opt for composition @ 1%.when the window opens in March 2019.

But as he's also in receipt of commission from company on which right now he collects gst and pays it. And he will continue to receive commission for next year also.

My query is whether he is eligible to take benefit of composition scheme for next FY 2019-2020 if he's in receipt of commission?

Thanks.