Your school receives 10-13 band 6's for chem so you are just in band 6 range
but only 4-8 for physics so push to be top 5 in physics
and also increase chem a bit and you are on your way
Based on the ranks, which correlate with your marks. The school rank doesn't actually matter at all, but it usually means that you have a stronger cohort than a lower ranked school.