Both in a way... Basically a credit average is what they'd expect as a minimum standard. If I'm not wrong, that's greater than or equal to 5.5/7 and a WAM of 65
I'm pretty sure it's your GPA that's most important, because they won't usually look at your transcript until you've passed the preliminary stages
It isn't impossible to get up there with a lower average, work hard and you can get there
but in that case you usually bed something which sets you apart from other applicants such as extracurricular's or previous work experience.