Engineering Entrance Exam

It depends on what you want to pursue. For NDA, your marks don't matter much. In NDA, they can choose a person with 65% marks and can also deny a person with 95% marks. They need personality, attitude and working abilities which will suit defence forces. While talking about IIT's they are the best colleges not only in INDIA but among the top 100 of the world {some, not all}. Getting into IITs is not easy but if you get into them the lifestyle, character, image, etc. will change and I am pretty sure that a person in an IIT is also among the respected one in the society.

Yes, JKLU is receiving the application for B.Tech currently. The admissions are live and you can fill the application form by visiting the website of the university- www.jklu.edu.in
You would not have to wait for the JEE exams and you can apply for engineering right away.

Earlier scheduled JEE Main April 2020 exam has bee postpone and scheduled to be held in the last week of May-2020. The exact date will be announced after assessing the situation in the coming weeks. So, there is no advantage to apply for JKLU right now. Because JKLU is also accepting the JEE Main scores for its B.Tech admission. Hence you have to completely focus on the JEE Main April exam and try to secure the rank below 30,000 for admission in top engineering colleges.

Yes, JKLU is receiving the applications for B.Tech courses. Please use this link for application process:
https://applications.jklu.edu.in/btech

First write the full form of JELET, then I will explain you.