I don't think it would be below your room as the crew quarters and other areas are still below the passenger decks. Hopefully, Cruise Fanatic will see this, I believe she has the ship layouts for every ship. LisaP, has sailed on most of the NCL ships, too.
I sailed on the Sky, and think I was on deck 6, but am not sure. Guess I need to dig out my information.
We were on deck 10 on the Epic and did the behind the scenes tour. On deck 2 and 3, they had the laundry, the walk-in freezers and coolers for different types of food, the bakery, then deck 4 was the galley. On deck 2 they had the garbage machines, and there were still more decks below before the engines.