Hello there. Hope you are doing good. I would like to tell you that you need to pass all subjects in your 10+2 in order to be eligible for air force. If you have failed one of your main subject, then your result will not be considered as passed. So, you can reappear for the compartment exam and pass the chemistry exam in order to be eligible for the exam.

I hope you found this answer helpful. Good luck for your future.