You would need an agent or manager to get you an appointment. Even once you find representation, the chance of them submitting you is slim and the chance of the casting director calling you in is even slimmer. You could find out when the equity required calls are and go, but unless you’re the next Alex Brightman or Idina Menzel, it’s probably not worth your time. Go to open calls for tours and cruises and work your way towards finding representation. Playbill has auditions that would be more worth your time listed often.
Just_John said: "You would need an agent or manager to get you an appointment. Even once you find representation, the chance of them submitting you is slim and the chance of the casting director calling you in is even slimmer. You could find out when the equity required calls are and go, but unless you’re the next Alex Brightman or Idina Menzel, it’s probably not worth your time. Go to open calls for tours and cruises and work your way towards finding representation. Playbill has auditions that would be more worth your time listed often."
You don't know why the OP asked the question, nor do you know what they are casting. To presume they are looking for the next Idina Menzel or one-trick-pony Alex Brightman is absurd.