JEE Main

Your AIR and state rank will be mentioned on your score card.

Jee Mains has a minimum requirement board % cut-off of 70%. Better you check it out on the JEE government website.

It cannot be determined before the examination, we can assume from previous year's cutoff, so it will depend on the cutoff of this exam, 70% will be needed to get you into NITs.

JEE Mains score will be decided after exam and college choice will be decided in counseling. Above 70% score will provide you the best engineering college.

You need to score a minimum of 40 percent marks in JEE Mains get admission in NIT.

You can check the link mentioned below:
http://www.result24.co.in/jee-main-2015-syllabus-download-pdf.html

Can I get the details of your academic performance?

JEE Mains is an all India entrance exam, so it is going to be tough. If you have to score high, you have to be good in physics. Chemistry consists of similar reaction, so it helps to score high. You need to be good in mathematics to score or crack the logic.
To prepare for JEE Mains, you must solve at least 50 MCQs per day per subject. Time management is the most important thing for any competitive exam. Usage of the shortcut is required to save time and score high.
In mathematics, don't prepare half section. You should study every section completely and then move on to the next section.

I think Allen is the best coaching institute for the preparation of JEE Mains and Advanced exam.

According to me, it is from CET but I will suggest you to prepare for JEE because the news is that CET is going to be cancelled for all engineering and medical students. If you will prepare for JEE and then there will be CET, it will not be difficult for you because JEE has little higher level then CET.
All the best.