Fortnite duo if you are in different divisions?

I want to play with a friend who is division 1 and I'm division 6 in which division do we play? I'm pc he ps 4

You play in the better one. If he were to play in the worse or in a lower one, he could simply score points.

First of all you have to be a group leader because you have more points. You will always play in the highest division. So in your case division 6. (since you are in this one) you also get a deduction, which your mate gets when he plays with you. I hope I could help. For questions, just let me know.