JEE Main

You can only get some of the GFTIs at this rank and not the NITs as you rank is quiet low to get into the NITs.

This year, you to should target for the 160+ in the JEE Mains and 135+ in the WBJEE to get the admission in this college.

Resonance and Allen are the best coaching institute for the JEE Mains. They provide knowledgeable/quality faculty members.

https://jeemain.nic.in/WebInfo/Handler/FileHandler.ashx?i=File&ii=86&iii=Y
You can download the above link for detailed syllabus.

Negative marking is also there. So, overall, JEE Mains is quite tough than CET, but the ratio of toughness depends on your preparation. MHTCET is focused on testing the breadth of your knowledge and JEE Mains is focused on testing your depth of knowledge; so don't compare their difficulty levels.

In JEE 2019, 12th marks don't matter to it but yes, you have to secure minimum 75% marks in the board exams, only then you would be able to get admission in the NITs and IITs.

I'll prefer you to join any other coaching institute like Allen and Resonance as the coaching institute mentioned by you is also quite good. But the main problem is that their passing ratio is not that good.

The eligibility criteria for JEE Mains counselling is to just appear for the JEE Mains paper, whether you have qualified the exam or not.
You are eligible for the counselling, but yes, if you haven't secured 75% marks in the boards exams, then you are not eligible for admission in any of the colleges through Mains counselling.

Yes, it's hard as JEE Main but not as hard as JEE Advanced. If you want to crack this, you have to clear your all concepts of 11th & 12th standard.

For getting admission in an engineering college, you have to apply for JEE exam. If your JEE Mains score is low, you can get a low NIT, but there are less chance for you to get a good NIT. Apart from this, you can get good government colleges in your area. To get admission in those there is a different counselling form for every state.