Hii!
As per the latest updates, CBSE has said that the exams specially of class 10th and 12th will be conducted as per the schedule and in offline mode only from 4 May, 2021. They will not be postponed as such. But, there are chances it may change or get postponed if the Covid 19 pandemic remains in the same state and is severe. However, there is no such official announcement.
So, keep preparing for the exam as per the datesheet provided and do not expect anything.
Hope this helps.
Good luck!