Hello Saurabh!!

You have not mentioned your Board but still I want to tell you that, In none of the board have this facility.

I accept that you have one additional subject, but it can't be Mathematics. This is the basic subject in which every student have to be passed and should have good score too, if he/she is having dream for better future .

You additional or optional subject might be Hindi, Computers and others but it can't be Mathematics.

As of new CBSE guidelines also, student can differentially choose their subjects between basic and standard Mathematics. But still student have to get passed in that.

Then only he/she will be able to get qualified and all five main subjects have to be qualified by you like Mathematics, Physics, Chemistry, English, Hindi/Computer etc.

As you have talked about eligibility of Air Force or Navy, it is not possible to apply because there is a minimum qualification of student to be qualified in 12th Board Exams with certain specific percentage.

So, don't get demotivated You can do Better and Give Your Best.

Hope that my answer helped You!!

Good Wishes and All The Best for your Future!!

Thank You