Hi aspirant,

According to the eligibility criteria set up by UPSC, the body which conducts the NDA examination a candidate needs to age between 16.5 to 19.5 years of age for being eligible. In addition to the age limit you must have completed your intermediate or be an appearing candidate. So following all this you would be eligible for NDA examination 2 2023 for the time and your last attempt would be NDA 1 2025.

Hope it helps!!