Gurnaj, NSTSE exam is held in the month of December. For session 2019-2020, the exam has already been conducted for classes 2 to 12 in offline mode on 4th and 15th December 2019.

Although if you are asking for the academic session 2020-21, the notice has not been released yet. The registration starts tentatively in the month of June. You can visit their official website: https://www.unifiedcouncil.com/index.html during May- June 2020 to know about the exact dates.