I think Physics and Maths are really important since, most exam have easy physics and maths and they are also usedas decider in the case of tie breaker.

In case of Competition all physics , chemistry  and mathematics are equally important.But let me suggest you that  Chemistry is high scoring subject.Please try to practise more from it you would easily clear any exam most from the chemistry part...

Best of luck

Shubham Goel(DTU)