CBSE have not released the any notification regarding when will the postponed exams will held. But here you can check all the latest feeds on CBSE.

cbse-board-exam-date-sheet (https://www.igens.in/date-sheet/cbse-board-exam-date-sheet/)

cbse-class-10th-sample-paper (https://www.igens.in/sample-paper/cbse-class-10th-sample-paper)

Hello Aspirant, There is no official notice regarding this but by seeing the situation of the country due to COVID - 19 , it is impossible to take exam just after 31 march. JEE Main which was to held in the 2nd week of April has been postponed till may,and NEET which was to be held on 3 may has also been postponed. There is no chance of Exam to happen in April or even in early week of May. I think it would be around last week of May or even may be in June or next month depending upon the situation.