A. You need to collect your NIOS Intermediate certificate which should have been done 6 months after passing the exams. After doing some background check, Ishan International Public School is listed as a study center for NIOS in Patna, Bihar.
B.You can get this done by
With a copy of all the doucments related to your intermediate enrollment, passing etc approach the study center administrative office, they would be able to help you or guide you at least.
C. The other thing you can do is contact the Regional office for NIOS of the various states (http://www.nios.ac.in/contact-us/regional-offices.aspx). For Bihar it is
Dr. Sandhya Kumar,,
Asst. Director,Regional Centre NIOS-Patna
This office should be able to help you once you provide your details.
D. Lastly, since it is more than 8 years, you can apply for a duplicate copy of the pass certificate for your intermediate. The charges are around Rs 200.00 and the contact authority is
The Section Officer,
M & M Branch,
National Institute of Open Schooling,
A-24/25, Sector -62, Institutional Area,
E. You can find the details at this link(http://www.nios.ac.in/student-information-section/procedure-for-obtaining-duplicate-certificate.aspx)
What you need is
1.The general application form to be duly filled can be downloaded (http://www.nios.ac.in/media/documents/migcert.pdf)
2. Original affidavit signed by a 1st class magistrate ( the format is in the second page of the general application form itself)
3. ID proof of your self and the certificates from NIOS
4. For postal delivery, you need to pay Rs 50 extra.
Which ever mode you use, please state clearly your roll number, exam date, the pass certificate number etc.
Keep the acknowledgments of any fax or email handy so that you can contact them for further clarifications.