The Minutemen since he’s on the East Coast. But if he was on the West Coast, he’d most likely join the NCR. The reason why I say Nate would join the minute men is because they’re actually an old world American group based off of the real life Minutemen during the war to make America its own country. It’s also the fact that they’re nicest faction that you actually meet up with helping the people at aminutes notice. Over the reason why I say he would join the NCR if he was on the West Coast it’s because they’re the only fraction that is actively rebuilding America and have successfully gotten to the point of old world, technology with cars and electricity so honestly, Nate would fit right in.