Hi candidate,

As you have mentioned that you appeared for class 12th in West Bengal board but you are not satisfied with your result so you want to apply for improvement examination from CBSE.

The criteria for appearing in CBSE improvement examination is that candidate should had given CBSE formal examination in the consecutive year. So, you are not allowed for appearing in CBSE improvement exam.

Also, there are no such provision of improvement examination in West Bengal board. But I suggest you to apply for rechecking the subject, that you consider you got less marks than expected.

I hope it covers your doubt.

Thank you!