Where can you get a legit Rayquaza in White Two?

In Pokémon White 2, you can obtain a legitimate Rayquaza by participating in a special event or by trading with someone who has it. Rayquaza is not available in the wild in this game, so events like Pokémon distributions or trading events are your best bet. Additionally, you can access Rayquaza through the Dream Radar if you have it, as you can catch it in that game and transfer it to White 2.