The age criteria for defense exams vary depending on the specific exam and the position for which candidates are applying. Generally, the minimum age requirement is 16-19 1/2 years, and the maximum age limit is around 19-25 years. However, age relaxations are provided for candidates belonging to reserved categories and those with prior military service, as per government rules.

Any candidate who meets the eligibility criteria can prepare for defense exams. These exams are open to candidates from various educational backgrounds, such as 10th pass, 12th pass, and graduates. The eligibility criteria often include specific physical fitness requirements, educational qualifications, and citizenship requirements. Candidates should possess qualities like discipline, physical fitness, mental agility, and a passion for serving in the defense forces.