Hi Vansh,

First of all if at all you want to improve your marks why don't you do it from CBSE board itself. Now coming to your question, it's not just JEE or NATA colleges but none other colleges accept marksheet or pass certificate from two different boards at the same time. So you must either reappear and improve your marks from the CBSE board itself or appear for all the subjects from NIOS and then use that one particular board certificate only, whichever you find it better.

Hope this answers your query.