I understand your frustration and the urgency of this matter. It is certainly concerning that you have registered for the JEE Mains second shift paper and have not yet received it.

Here are the steps you should take to raise a complaint and seek immediate resolution:

1. First, go to the Careers360 website . Look for "Contact Us" or "Support." You should be able to email, call, or fill out a form. Tell them you signed up for the JEE Mains second shift but didn't get it, even though you gave them your info. Say when you signed up and any numbers they gave you.

2.Next, go to the official NTA (JEE Mains people) website . Find their help numbers, emails, or a place to complain. Tell them the same thing: you registered for the second shift and didn't get it. Give them your name, application number, etc.

3.Also, save any emails they send you or any numbers they give you when you talk to them.

I hope this helps.