Oxford PPE/reapplication ?

I applied to Oxford last year for Mathematics and got rejected pre interview - didn't pass the test - so after a year of deep thoughts I decided maths wasn't the subject for me anyways - I may have been pushed by my parents expectations too much - and decided to apply for a subject I felt enormously more inclined for which is PPE.
A huge doubt however has arisen : will Oxford see my past application even if I apply for a different college ( I wanted to apply to Balliol this year - is it too risky given the high competitiveness ??? ) and decide my academic motivation isn't strong enough to make it through ?
One last doubt I know Oxford cares hugely about GCSE , however my parents and I moved to France when I was 10 resulting in me pursing a French Diploma , consequentially I will only be able to show them the final grades I achieved in the diploma , would that be alright ?