When calling bought Tribe members, do 6s get rerolled?

Uhm, context?

That sounds like a SR2 question! (In SR2, in addition to contacts rated as Contact, Buddy, and Friend for Life, you could also elect to join a gang or tribe, which gave you a small army of minion NPCs to help you.)

If that's the context, I don't believe that you re-roll 6's from that, as it's not a "test" per se. Re-rolled sixes could easily be a house rule for them, however; I don't think it would be game breaking. All of this off of the top of my head, and it's been over fifteen years since I played second edition.

If you're talking about something else, then I have no idea.

Sorry. Yes, it is specifically regarding 2nd edition. I wasn't sure to what other editions it may apply. Reroll or not is ok with me but I wanted to try to get it right. There was some interest in getting a 2nd edition and /or 3rd edition game together on roll20 so we could use voice.