The minimum age limit for NIOS 12th Admission is 15 years. A student has to complete 15 years to take admission in the Senior Secondary Course. Also he/she should have completed secondary course (10th Class) from a recognised board. Those who could not continue studies after passing 10th class can also apply for NIOS 12th. There is no maximum age limit to apply for admission to NIOS board. Those having long gap in the study after 10th, can also apply for NIOS 12th.