Need help joining a cracked server

Hey I am trying to join a cracked server with 1.6.6 but I don't know how.
Am I supposed to download something? I believe you're supposed to click Play offline but it gives me a "(not downloaded)"

Anyway Idk how to play cracked servers and I'm fairly new to minecraft. I think I'm going to get a premium account.

I think you can just connect to this server without pressing anything its their side that sets it to offline

I'm pretty sure this happens when you get a real minecraft client and not a hacked one and you haven't started the game with a real or fake account. Kinda hard to explain.