Hi Prakash,  cse and ece are two different branches of engineering. While in cse, you will be focussing mainly on computer programming, softwares etc. It is the most popular choice among BTech aspirants as it offers best placement opportunities. To Know more use this link

https://www.careers360.com/computer-science-engineering-course

Ece is also a very popular branch. You will initially learn about semiconductors and stuff. It is branch with alot of scope so it's a great choice. Use this link to know more.

https://www.google.com/amp/s/engineering.careers360.com/articles/electronics-and-communication-engineering-0/amp

Hope this helps. Regards