Hello,

Yes, you can enroll in National Institute of Open Schooling and give the exam. You can enroll for On Demand examination through NIOS and appear for the exam whenever you are ready to give the exam. NIOS On-Demand Examination will not be conducted during the month of April, May, October and November. So you can give the exam in any month except in the month of April, May, October and November. The fee to register for one subject (theory) is Rs. 500 and for Rs. 200 for practical subject.

To enroll visit the official website

https://www.nios.ac.in/on-demand-examination/on-demand-examination-system-registration.aspx