IIT

NCERT books are very good. You can solve the entire exercise. This will help you a lot. I would suggest you to first complete the NCERT exercise and examples, then do exercise and examples of the same chapter or topic from other books.
Best of luck.

ISRO regularly advertise their open requirements of Scientific Officer. IRSO hires B.Tech or M.Tech ECE /CSE/ Instrumentation/ Mechanical/ Aeronautical Engineering or M.Sc Physics / Astrophysics etc . You may chose any of the above mentioned options to join ISRO.

It is difficult to say anything about the minimum cut off. Every year, the minimum cut off changes. It ranges from as low as 60-70 percentile to higher percentile of 80. So let's see what they decide this year.

I think, B.Tech from IITs is better because University of Berlin got 119 rank and IIT - Delhi has got 150 rank.
1. After completing B.Tech from Berlin, you will face problem related to placements because foreign universities don't allow you to sit in campus placement. If you want a job in Germany, you will have to apply for visa.
2. In IITs, there is no such problem. You will be able to sit for placement and get high package.
3. The process to apply for foreign universities is complicated it takes approximately 2 years.
4. But for IIT, you only have to qualify JEE Mains and Advanced exam.
You can go for Berlin to pursue Master's degree.

Under formal education B.Tech, BE and B.Sc are engineering degrees offered by Indian universities.
Following are major specializations available in engineering:
1. Aeronautical.
2. Biotechnology.
3. Civil.
4. Chemical.
5. Computer science and engineering.
6. Electrical.
7. Electronics.
8. ECE.
9. EEE.
10. Information technology.
11. Instrumentation.
12. Industrial.
13. Mechanical.
14. Mining.
15. Metallurgy.
16. Petroleum.
17. Production.
18. Textile.
19. Marine engineering, etc.

IITs and IIITs do not have the provision for lateral entry admission in 2nd year in their graduation programs.

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

Hello Kapil,
CBCS allows students to select from a variety of courses offered by a particular college to get credits and obtain desired degree. Majority of institutions abroad have this system in place as against very few in India. You will have to go to website of UGC to know in detail.

Yes, they do offer this course.