Hii Munna!
If you are talking about Central Hindu School, Varanasi, then, the admission process for class 11th has started. The online registration form has started in the month of April, 2020. The admissions are provided via the entrance exam named School Entrance Test (SET), conducted by BHU. The exam will be conducted in the month of May, 2020. You can visit the official Website and fill the application form.

http://chbsbhu.in/Procedure.aspx

Hope this helps.
Good luck!