Hello dear student,

First of all it's completely fine if you failed in your previous class but it what is more important is that you come out of that and prove yourself. It's completely fine and don't give it away too much importance that it makes you feel sad. Just forget and move forward with the victory you have achieved.  And yes nios board is very much makes you eligible. It's parent organisation is ministry of Human resource and development. So if you give some government exam then there is no point to worry . It doesn't make anyone question or makes you less eligible.

I hope this helps

Thank you