Hi aspirant,
Different iits provide a bit varient courses and have difference in top five branches.
At IIT delhi top five branches are-
CSE,
EE, CSE and Mtech,
EE and Mtech and
EE(power).
At IIT kanpur top five branches are-
CSE,
EE,
CSE and Mtech,
EE and Mtech and
ME. The link below contains all the information of all IIT's with their top five branches, follow it to know about all iit's-
https://www.askiitians.com/iit-jee/top-five-branches-at-different-iits/
Hope this helps!!

Dear Avinash,

Different IITs and NITs are famous for different branches. Like

1. IIT Bombay: Computer, Mechanical and Electrical Engineering are the most popular mainstream branches. Electrical Engineering with M. Tech. in Microelectronics(5-year course) is also a popular branch here.
2. IIT Madras: Computer and Mechanical Engineering are two of the most popular courses here. Computer Science & Engineering a 5-year dual degree course is also very popular course offered here.
3. IIT Delhi: Computer and Electrical Engineering are two most sought-after courses here. Mathematics & Computing is also becoming a popular course these days.
4. IIT Kanpur: Computer and Mechanical engineering are in high demand here. A 4-year B.Sc. course in Physics is also much in demand here.
5. IIT Kharagpur: Computer and Electrical Engineering are the most popular courses here. Instrumentation Engineering is also a very demanded course here.
6. IIT Roorkee: Computer and Electrical Engineering are the most demanded courses here. Production & Industrial Engineering is also lately in demand here.                             Whereas if you ask the highly paid jobs then its Computer Science Engineering offering Rs. 2.4 Lakh to Rs. 1 Crore per annum. This is the average but if you complete from IIT it has a great scope. Theres nothing like top branches, I think. It all depends on your potential and your knowledge in that respective field. It is a dream of most aspirants to get an admission into these branches.   

Hope this helps! All the best!