I'm asked to join to an US Normal/PVP/RPPVP server

[Arixtra]

As soon as I try to choose a realm, I'm asked to tick US as preferred region. Furthermore I can choose between PVP, RP, PRPVP, but nothing according to Nostalrius.
My realmlist.wtf text is already set to "set realmlist login.nostalrius.org"
I'm playing on a macbook. Can anybody help me with finding and entering the right realm?

[AverageJoe]

It shouldn't matter what you select; the game will suggest a realm for you anyway that may or may not be the right realm. The correct realm it should suggest is "Nostalrius Begins," but I've seen it suggest one of the developers/test realms before.

If it suggests any realm other than "Nostalrius Begins," click "Choose Realm" and manually pick "Nostalrius Begins" yourself.