My son is overreacting to me pranking him.
In what way did you prank him?
I sent few people to his house pretending they want to make a deal there.
It sounds like you went too far with your prank. You should apologize to your son and try and regain his trust.
Nah, I don't think it's that big of a deal.
While you might have certain limits when it comes to pranks you son obviously has differing ones. Your prank violated his trust and it's reasonable for him to be feeling this way. You should apologize so the two of you can move on from this situation.