CBSE

I will suggest you to first strengthen your fundamentals as it is very important for your class 11th and 12th board and very well needed for the IIT exam. IIT exam is not a rocket science, you just need to be more dedicated to proper time management as you have to balance your 11th with IIT preparations.
For example, if you read Kinematics, I will suggest you to make your fundamentals strong with a standard book or any other means with which you feel comfortable then solve your class 11th questions first and analyze yourself and then refer to the previous year question papers of IIT and try to solve them as well and analyze your solving skills and time management.Just remember, to achieve something different, you have to do things little different.
I hope that this will help you to decide what to do, and if you have any doubt, feel free to ask.
All the very best for your future!

Starting from the point of view, hacking doesn't requires eligibility of academics. Hacking is just a skill which requires, Coding Knowledge, Network Knowledge, Server side Scripting Knowledge, Computer Hardware Knowledge and Testing Knowledge. Coming to the part, if you saw the articles, the children are around 5 - 11 years of age are hacking networks, finding zero day flaws in software etc. So this shows hacking doesn't require any academic courses. Learning hacking through any certification such as EC - Council CEH, (ISC) 2s CISSP, CISA and CISM from ISACA and OSCP from Offensive Security will improve the professional skills of hacking.
For more details, check the link below:
http://www.gangte.net/2014/03/how-to-become-a-hacker.html