Hello aspirant,
I hope your academic progress is going well. As for your question, you can switch from the ICSE to the CBSE board after the eleventh grade. Simply get in touch with the institution you want to attend, and they will inform you of the process. You might need to visit the board's regional office and obtain some paperwork as well.
And yes, you should have a valid cause for doing so as well; otherwise, it would be difficult for you to get permission as, as you are probably aware, you should complete your +2 at the same school under the same boar d.
Thank you
Hope this information helps you.
Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile