Apprenticeship whilst in sixth form?

i want to do an apprenticeship but i also want to go to sixth form and i don't know what to do and it seems what ever apprenticeship i apply for they say no and i think its because i am starting sixth form in september but my parents are saying that its because i have no got my results yet but i have said what i am predicted and most of my exams are Ds i only hv 3 subjects that are A*-C