Which engineering branch would be better in terms of scope?

All of the branches are best according to your interests. If you want a govt. job, you should prefer civil engineering or if you want to do a private job you go on CSE /IT/ECE, it is all about your interest.

Really speaking, every course in engineering has a good scope in future. The only thing you have to do is to excel in your course.

I would like to suggest that do not take any stream just because anyone has suggested you. First, analyse yourself and then decide that what you want to learn. Where you have interest. Then select a branch.

As most of students are going towards computers, by this time world also need a cheap renewable source of energy that is renewable energy. So I would suggest you to do engineering in renewable energy branch. But you should choose on what is your interest as you can do much better in that engineering

It basically depends on your interest. If you have an interest in construction then go for civil engineering and if your interested in computers then go for IT and CS, its scope is more than civil, and mechanical.