Can I register for NIOS after JEE Main if I only need it for the 75% criterion?

My situation:

• Passed CBSE Class 12 in 2026.
• Appeared for JEE in 2026 but didn't qualify.
• Also scored below 75% in CBSE.
• I skipped the July 2026 improvement exam.
• I don't want to give exam as cbse private student for next year.

I still have JEE Main attempts left, and I know that for admission to most NITs/IITs through JoSAA I need either 75%.

I want to register for NIOS only after giving my jee attempt, so I know it is worth it to register if I did good in jan/apr attempt next year.

I've been looking at NIOS Stream 4 (On-Demand Examination), but I'm confused about the timing.

My question is:

Do I need to register for NIOS before JEE Main, or can I wait until after the January (or even April) JEE Main attempt and only register if I actually get a good rank?

For example:

• Give JEE Main January attempt.
• If my percentile is good enough for an NIT, then register for NIOS Stream 4 (Physics, Chemistry, Maths, and English) and appear through ODE to obtain the required marks before JoSAA.
• If my JEE rank isn't good enough, then I won't spend time and effort on NIOS unnecessarily.

Is this sequence actually allowed, or is there any rule requiring me to be enrolled in NIOS before JEE Main?

Also, is there any alternative to NIOS in this situation that people have successfully used?

JOSSA need 5 subject and NIOS ODE only allow 4 subject, and only way is giving NIOS public exam, and the deadline for filling that exam registration will end the month. There is no way I can register for NIOS after JEE first attempt in Jan?

Here is what I found in Google:

A student who has already passed Class 12 cannot officially register for a full 5-subject fresh certification under Stream 1. Instead of a fresh 5-subject registration, passed-out students must apply under the Part Admission / Dual Enrollment scheme.

You must present your original Class 12 passing certificate along with this new NIOS marksheet to college authorities or employers during document verification.

Is this true?