Visa for Nursing OSCE

Hey everyone, I was wondering if anyone applied for a 651 visa to do the Aphra OSCE exam?

Also, I was thinking to do an English Language course, and apply for a 500 visa instead. I read that you can enter the country 3 months before the course starts, could I do a 2 week OSCE course + OSCE exam during those 3 months my 500 English course visa? Thank you!