Hello, I hope you are doing well

Yes, You can do so but only if the school or institute you are studying in allows you to do so.

Otherwise you can appear as a Private candidate for Board exams, in any of the cases you will have your practical marks similar as that of previous one and will have to appear for your Theory paper only.

It depends on the school in  which you wanna read or complete your 12th exam.

Following is the basic Difference between a private candidate and a regular candidate:

https://www.careers360.com/question-difference-between-12th-private-candidates-and-regular-candidates-in-cbse-board/amp

Hope this helps

All the best!