NIOS is the National Institute of Open Schooling, a national board under the Ministry of Education that offers flexible, open and distance education up to the secondary and senior-secondary levels. It lets learners study at their own pace and sit examinations when ready, which suits working people, dropouts and students who need a second route to a Class 10 or 12 certificate. It is one of the three national boards, alongside CBSE and CISCE.
In Indian schools
Open-schooling and distance learners enroll, pay and complete on their own timelines rather than in fixed yearly batches, so the admin skews towards flexible enrollment and fee plans. That learner-lifecycle administration is what a system built for training and flexible providers handles well.