Hii!

• For Army Wing, you need to have passed 10+2 or equivalent examination conducted by by a state education board or a university.
• For Air Force and Naval and 10+2 Cadet Entry Scheme at the Indian Naval Academy you need to have qualified 10+2 with physics and mathematics or equivalent examination conducted by a state education board or a university.
• You can also take the examination if you are an appearing candidate of 10+2 examination.

So basically you have to be in 12th standard to take the examination.