I had the exact problem I got 4 GCSEs yesterday and I thought that was it for me I got two Bs in English language and RE/RS and 2 Cs in ICT and science the rest were all Ds my school told me I need 5 GCSEs to get into sixth form but due to my high mark in English and RE I was given a place in my sixth form after being turned down originally, so now in my a levels I'm doing Law, media, sociology and maths retake ( as I failed maths ). and if this happens to anyone else don't feel defeated if you get good grades with the 4 you pass don't feel defeated talk to your enrolment teachers and they will help you and more than likely offer you a place. PS they say you need 5 GCSEs but you can get in with 4 as long as you pass English language or maths but yesterday was such a tough day for me but I was so happy to be allowed in to my sixth form due to my English mark.