I hope you are doing well.

Yes you can change your board from up board to cbse in class 11th , as registrations for both 11 and 12th class will take place in your 11th class only.

In fact, many students make this switch with the aim of improving their grades because state boards like UP can be relatively challenging, making it harder to achieve high marks. If you are a reasonably proficient student, CBSE offers a greater opportunity to score above 85%. Therefore, it's essential to make your choice wisely.

I hope this answered your question