IIT

You may refer to the following link for a list of top aeronautical engineering colleges in India : https://www.shiksha.com/top-aeronautical-engineering-colleges-in-india-rankingpage-49-2-0-0-0

For ethical hacker, you need to take some other specialisation course. It will be a certification course. IIT JEE is required to pursue engineering in different fields.

Hi,
Yes, there is a reservation for physically handicapped student in IIT.
Persons with disability (PWD) 3% seats in each of open, OBC-NCL, SC and ST category seats. The benefit would be given to those, who have at least 40% impairment irrespective of the type of disability i.e., locomotor, visual or severe dyslexic.
Leprosy-cured candidates who are otherwise fit to pursue the courses are also included in this sub-category.
You can check the below mentioned link for further details:
http://www.jeeadv.ac.in/info_brochure
All the best.

Yes, it is necessary to clear IIT-advanced to get admission in IITs.

To get admission in NITs and IITs, you need a strategy. You need to make your basics clear and rigid so that you can move forward. You can read NCERT books. You should practice as it will help you to understand the theories in a better way and also you will come across some unknown methods to solve a particular problem.
You can collect the previous year question papers with their solutions as it will help you to analyse the pattern. You should revise the areas in which you are strong, but work on the areas in which you are weak.
Best of luck.

BITS-Pilani, VIT University, Manipal University, Thapar University, SRM, BIT are recommended options. You may refer to following link for ranking of top engineering colleges in India: https://www.shiksha.com/top-engineering-colleges-in-india-rankingpage-44-2-0-0-0

There are some coaching that offer free IIT preparation by conducting some exam for their coaching institutes. By giving those exams, you can get admission in those institute that will lead you to free coaching.
Examples are: Super 30, Anand Kumar Institute, etc.

It is a newly started program in IIT and it will take some time to get momentum. However, considering reputation of IIT, you may expect average package of Rs.5 LPA.