National Institute of Open Schooling (NIOS):

It's an autonomous institution under the Ministry of Education, Government of India. NIOS provides education through distance learning mode, catering to a wide range of learners who want to pursue education at the school and pre-degree level but cannot attend regular classes for some reason. It offers courses equivalent to the formal school system, including secondary (class X) and senior secondary (class XII) education.

courses:

NIOS offers various courses at the secondary (10th) and senior secondary (12th) levels, as well as vocational courses and courses for adults. One of the key features of NIOS is its flexible learning approach, allowing students to study at their own pace and schedule. It also conducts examinations twice a year, in April-May and October-November, providing multiple opportunities for students to appear for exams and complete their education.