Answer:
In french its: 6eme classe, 7eme classe, 8eme classe, 9eme classe, 10eme classe, 11eme grade, 12eme classe. (or grade for all but that's more slang.) for the actual words its six,sept, huit, neuf, dix, onze et douze
12th grade is also commonly referred to as << le terminale >>, as it marks the transition period between high school (lycee) and college (universite).