Ranking Criteria wrote:
If the drain time of the highest difficulty is...
...lower than 3:30, the lowest difficulty of each included game mode cannot be harder than a Normal. Because osu!mania does not have a difficulty-specific Ranking Criteria yet, an osu!mania beatmapset's Normal difficulty is defined as a difficulty below 2.00 stars. For hybrid beatmapsets that include osu! difficulties, the additional modes’ lowest difficulties cannot be harder than a Hard.
...between 3:30 and 4:15, the lowest difficulty of each included game mode cannot be harder than a Hard.
...between 4:15 and 5:00, the lowest difficulty of each included game mode cannot be harder than an Insane.
...anything higher, the beatmapset is exempt from reasonable spread rules.
So for 4:30, you don't even need a hard, you can just have a single insane. Note that the diff requirement isn't "x or above", it's "x or below". For future questions concerning rankability, you may want to check out the
general Ranking Criteria and the mode specific Ranking Criteria of your preferred game mode, linked at the top of the general RC.