No iDevice with an A5 chip or higher can be downgraded from iOS 6.0.1 to any version of iOS 5 or earlier. This includes iPhones, iPads, and iPods.
willerz2 said:To clarify, the only iPads that can be downgraded through the iOS 5/6 barrier are the iPad 1 and iPad 2s. And for all other devices, pre-A5 are the only ones downgradeable.