Firstly, try to figure out why does he turn aggressive. What makes him angry?
Some kids tend to have such behaviour and reason can be that he is hyper-active and he has too much energy that after a point of time he gets bored and gets aggressive because of this boredom. I suggest, you enrol him in a play school or some extra-curricular classes so that he has something new to get engaged into. He will have other kids around and slowly and steadily under the guidance of the teachers in the play school, he will learn how to behave with other kids.
It will take some time but he would be fine. Brief the teachers in the play school about how he turns aggressive so that they can particularly address this issue. And if you still don't see a change then you can see a child psychologist. They interact with many cases like such and they know how to deal with a kid. It must be a normal issue which can be sorted with little counselling, so do not worry and don't lose your peace of mind.
https://www.empoweringparents.com/article/hitting-biting-and-kicking-how-to-stop-aggressive-behavior-in-young-children/
https://www.loveandlogic.com/articles-advice/helping-aggressive-toddlers-and-preschoolers-started-before-its-too-late
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