Just Dance supports six players at once on eighth- and ninth-generation consoles.
That six-player figure describes the standard multiplayer capacity for the relevant console versions, allowing a larger group to dance together in the same session. The exact input method depends on the platform and game: players may use motion controllers, camera-based tracking, or smartphones running a controller app.
The generational detail is important because earlier hardware often had lower limits. Seventh-generation console versions and several Wii U releases were generally limited to four players. Some platform-specific modes also impose their own restrictions; for example, certain Dance Crew routines or older controller configurations do not necessarily support the headline maximum.
Just Dance began on the Wii in 2009 and expanded across Xbox, PlayStation, Nintendo, PC, Stadia, and mobile-based control systems. The series is designed for group play, but “six” should not be read as a universal limit for every edition, platform, or special routine. It is the canonical answer to the question’s stated eighth- and ninth-generation-console context.