Ideally pupils will have studied music theory hand-in-hand with learning an instrument / singing and so when the time comes to take grade 6 practical, grade 5 theory will have already been passed or the pupil will be able to take and pass it soon.
However, this doesn’t always happen. So, what are the options?
1. Pass grade 5 theory as soon as possible but keep on practising, then take grade 6 practical.
2. Work to pass grade 5 theory but keep on practising, skip grade 6 practical and go straight to grade 7. This gives extra time to gain the theory qualification.
3. Already got a grade 5 or higher pass in Practical Musicianship or a solo jazz subject? If so, either of these gives exemption from having a grade 5 theory pass.
If not, would it be easier for you to pass either of these exams than to pass grade 5 theory?
4. Consider a different exam board which does not have any theory requirement to enter for higher level practical exams, for example Trinity, MTB or London College of Music.
(Disclaimer – as far as I know, the above information is correct but please check the syllabuses yourself to make sure. I take no responsibility if any the above is incorrect.)