Class 11

You can't do it after 11th. Pursue 12th first and then give JEE Mains and Advance, if you get a good score, you can do aeronautical engineering.

There are a lot of career options after 12th.
B.Tech.
BCA
B.Sc
Polytechnic and more and more just go through the internet.
Many of your seniors will advise you to choose B.Tech CSE but you should pursue that particular one in which you have passion and interest.
All the best.

To teach in a public secondary school, a Bachelor's degree in computer science is usually required. A semester of student teaching is also needed and is usually completed within the Bachelor's degree program. A Master's degree is typically the minimum educational requirement to teach at a college or university.

Follow the article below for all the details:
http://www.gangte.net/2014/03/how-to-become-a-hacker.html

Hello Shree,
Students who use their time well can crack the exam efficiently. Therefore, it depends upon your potential of studying and gaining from your study. Studying 10 hours a day with full concentration is enough to crack the exam.
All the Best.

Hello Niveen
In your class 12th exam question are only from 12th Syllabus but if you wants to score good in engineering entrance exam so covering 11th portion in necessary here are the few important topics which you can cover to score good marks
Mathematics
Conic Section, Andhra Pradesh&GP, Limits, Permutation & Combination
Physics
Gravitation, Sound Wave, Fluid Mechanism
Chemistry
Chemical Bonding, Thermodynamic, Equilibrium, Hydrogen, General Organic Chemistry, States of Matter.

There is no any restrictions in taking or choosing any course or subjects in class 11th. So, choose anything on your passion and focus on it. Enjoy and learn the subject carefully.

Hello,
Diploma courses are the short duration courses
They are basically:
Diploma courses after class 10th
Diploma courses after class 12th
Graduate Diploma Courses
Post Graduate Diploma Courses
You can make your career in Engineering field by doing short-term courses too.