Dear aspirant,

You can give 12th board from NIOS board but it's of no use because you have studied commerce in 11th and 12th and so again if you study science it would be a waste of time but still if you insist and want to crack jee mains you need to be very dedicated towards your study .

Hi

As per the page number 10 of nta  JEE mains 2021 information brochure , students of NIOS are eligible for jee provided they pass with at least 5 subjects. You can check it on your own ,the link to download the information brochure is provided below
main, https://jeemain.nta.nic.in/webinfo2021/File/GetFile?FileId=1&LangId=P

So,
Yes, you will be eligible for JEE main examination after NIOS on demand examination but yes you will have to  give  with at least five subjects.

Now,
Eligibility criteria says that:-
-) to be eligible  for JEE mains 2021 for BE or Btech you should be either appearing for 12th board exam or equivalent  in 2021 or should have passed it in 2020 or 2019 with Physics,  mathematics and anyone of Chemistry or Biology or Biotechnology or Technical Vocational Subject.

So, now that you will be appearing for NIOS on demand examination with the five subjects, those 5 subject should include one language like English etc and physics and mathematics along with anyone of
-Chemistry
- or Biology
-or Biotechnology
-or Technical Vocational Subject.
For the 5th subject, you can choose any subject of your choice

-) There is no age limit to be eligible
-) there is no minimum percentage requirement to be eligible for JEE Mains, you just need to have passed your 12th

But yes,
To be eligible for NITs, IIITs, CFTIs one needs at least 75% marks in class 12th if belongs to General or OBC category or or at least 65% marks in class 12th if belongs to Sc or St category. For this year i. e 2021 this minimum percentage requirement of 75% - 65 % has been lifted off.

For detailed information about jee main eligibility criteria  go through our page, the link for which is provided below

https://engineering.careers360.com/articles/jee-main-eligibility-criteria

If you have any other doubt then you can always reach us to clear them :) we are always available to help you out and guide you

Thankyou