JEE Main

For taking admission in IIT, you will need a rank below 1500 and marks at least 250+ in JEE advance to get easy admission in aeronautical engineering. I hope this will help you.
Good luck.

Various institutes conduct their own exams for Diploma in various streams. So, you will have to check with your desired college.

Hi, Please find the link below:
https://www.shiksha.com/b-tech/articles/jee-main-how-to-attempt-questions-and-maximise-your-score-blogId-13982
https://www.shiksha.com/b-tech/articles/eamcet-2014-last-minute-tips-to-secure-a-good-rank-blogId-8218.

No, it is not possible for you to get into NIT or IIIT. Even if you have reservation, it would be hard for you to get a seat.

If you want, you can participate in that counselling but look, counselling rules and all the instructions carefully.

As you are a SC category student, you will need to score at least 250+ to get admission in IIT.
All the best.

It's not possible to do

I will suggest you to join test series of any renowned coaching institute and follow the syllabus regarding every test you will be giving, I will personally suggest you to join the test series of Allen as it's test series starts very early and is taken in a very qualitative manner according to the syllabus and if you will follow even 50% to 70%, by the time of your Mains exam you will be done with your syllabus and will have a good time for revision and practice which will definitely help you in your exams.

Not sure. It can be either way around given that counseling rounds are happening.

You need these book:
Loney's Coordinate Geometry and Trigonometry
Hall and Steven's Geometry
Hall and Knight's Elementary Algebra and Higher Algebra
Calculus by GP Thomas
University Physics by Resnick and Halliday
University Physics by Sear Zemansky
Problem in Physics, Irodov
Organic Chemistry by Morrison Boyd
NCERT book should be studied first.