I suppose you mean the Atlantis resort and casino on Paradise Island in the Bahamas? If so, all cruise ships that stop in Nassau, Bahamas offer an excursion to Atlantis.
Here's a list of ships
that stop in Nassau.
You don't have to take the ship's excursion, either; it's easy to get to yourself, by taxi or water taxi. It's worth seeing once, but I personally thought it was a bit overdone. The charge to see the aquarium ("The Dig") is $25 per person. It's a matter of opinion, but I thought that was overpriced. The casino, of course, is free.