sorry but i do not know whats the procedure for us students i think may be it is same as of indian students
u need more than 50% marks in both your 10th and 12th grade sorry dnt knw whats its called in ur country

maybe high school
here we have to submit total one year fees which is $13000 and than pay for gic $10000 and then do medical and then apply for visa btw why r u worried why u think ur visa will be rejected ??