Hi! They really look at what studio they think would suit you and your needs best, so it sounds like you have a pretty good idea of what’s going on. For example, if you show a strong passion for musical theatre, they might put you in New Studio on Broadway, which is the studio with the musical theatre focus. This gets more subtle when looking at the non-musically focused studios, but you get the idea. The only studio to which you would apply directly is the Production and Design studio. I’m in that studio and it’s pretty understandable that we have a separate process considering P&D is looking for vastly different qualifications than the acting studios (if they asked me to do an acting audition they’d be very dissappointed)!
After you complete two years with the studio you’re assigned you can transfer into a different studio including P&D (usually there’s an audition involved) or get an internship to fulfill the last year of your training.
Hope this helps!