Hi,
Let me inform you that there is no branch in which there is a job GUARANTEED.
As per the demand is concerned,it totally depends on the conditions of the Market.While,CSE,IT and ECE can fetch you higher packages in MNC's,you get the job security by getting into PSU's through core branches which offer a handsome pay check as well.However,I would advise you to not look into package and stuff,rather go into the branch which interests you.As you are currently in 11th,you still have a lot of time to decide.Take your time and choose wisely and try to follow your passion.
Hope this helps.

https://www.astronite.in/2018/08/flexible-loudspeaker-will-stick-to-your.html?m=1

CSE, ECe and IT have nost demand if done from top 100 Institute and must have good academic and fundamental. 

List of all top colleges below. 

https://engineering.careers360.com/download/ebooks/top-engineering-colleges-in-india-2018

Job guarantee will depend on how well your resume stands out and how good you are against competition.