Read our Armed Forces articles
Being a pilot in the RAF is generally very difficult. Most people do not pass the specific pilot entrance exam, at least not the first time that they attempt it. As far as I know, you need to get though officer selection first before they’ll even consider you becoming a pilot.
If you were looking at Pilot, do you have the required higher qualifications, and are just short on GSCEs? In which case, can you study and get the exam results you need? All officer roles need GCSEs.