is equivalent exam and a single sub backlogging and apperaing tat sub as a private canditate are same?

Hey,

Usually equivalent examination means giving NIOS examination or diploma examination. These examinations are not exactly like 12th standard boards, but are considered equivalent. Giving a single subject examination as a private candidate is also equivalent since you have a passing certificate of 12th after that. So you will be eligible for all the examinations.

This is a list of examinations considered equivalent to 12th:
1. The +2 level exam in the 10+2 pattern of examination of any recognized Central/State Board of
Secondary Examination, such as Central Board of Secondary Education, Council for Indian School
Certificate Examination and New Delhi
2. Intermediate or two-year Pre-University Examination conducted by a recognized Board/University.
3. Final Examination of the two-year course of the Joint Services Wing of the National Defence
Academy.
4. Any Board/Public School/University Examination in India or in foreign countries recognized by the
Association of Indian Universities (AIU) as equivalent to 10+2 system.
5. H.S.C. Vocational Examination.
6. Pass grade in the Senior Secondary School Examination conducted by the National Open
School with a minimum of five subjects.
7. Atleast 3 diploma recognized by AICTE or a State Board of Technical Education
8. Senior Secondary School Examination conducted by the National Institute of Open Schooling with a
minimum of five subjects.
9. General Certificate Education (GCE) examination (London / Cambridge / Sri Lanka) at the Advanced
(A) level.
10. High School Certificate Examination of the Cambridge University or International Bacca

Hope this helps!