Usually you are notified about 7 to 8 weeks prior to the start of the class. Gives you time to get the Trainee Visa and the contract agency does your background check. Also allows you to have some time to review the contract and do other other paperwork. I know somebody in November class and sorry, it is full.
Gomets, usually hiring is 4 AJV & 4 AJX every other month. That is 8 total, AJX is FO's only and AJV is FO's and Captains(any combination, not 2+2). So there are very few slots, even if you passed the medical and the interview you might get a call later that you are not going to be selected. Seems to me that they purge lowest scores from the hiring pool quarterly. (happened to my friend, 4 months after interview). Be prepared that it can take easily 6 to 8 months from a date your application is in to your class date.
Make sure your logbook is up to date to the minute, it will be checked very carefully multiple times.