Hello,

The details of NIOS exam for Stream 1 Block 1 of class 10 (or Secondary School) are published on the official site.

Link:

https://sdmis.nios.ac.in/

According to the online post, the candidate registered in the academic year 2019-20 can appear in the exam for the first time in the month of April/May 2020.

The exact dates are not yet published.

Hope this helps.

Thanks.