Hello Vaibhav,

I would like to tell you that you can study from both the boards but I would prefer you to stick to one board which is more comfortable.

However, if you want to keep both the options open, you can give the board exam from CBSE and wait for the results. If you are not satisfied with the result, especially if you fail in 1 or more subjects, you can appear for the "on-demand" exam of NIOS. The syllabus of NIOS is very similar to that of CBSE. so you should not find it very difficult to prepare for the exam. But your final mark-sheet will be from NIOS board, including the marks of the subjects you passed or scored satisfactory marks.

Hope this helps and all the very best!