Before answering I would like to make you aware that I completed B.Tech in Civil Engineering. So my views regarding all the other branches may not be completely right. I am writing this based on what I know. Don't completely depend on this answer for taking your decisions.

CSE

It belongs to the IT world. In this you have to study all the programming languages and the related aspects. If you study this branch for engineering the jobs would be white collar in AC rooms. Jobs are easy to get in the initial stages even if you are an average in your academics. Just like that, you can easily lose your job if you don't perform upto the marks. Experience dosen't have much role in the job fields. If you have real talent you can acquire higher positions and success will be quick. Good placements will be present at the college level if you are studying in a decent college. Now the con is that, now a days the older people in this field are losing their jobs. They need fresh new ideas in the IT sector. So as soon as you age more and you fresh ideas starts vanishing plus if you have been an average in this field , then the chances for losing your job is more.

CIVIL

Well this is my field. Civil engineering is said to be easier to learn than any other branches. Because what you learn here is what you can see in your daily life if you have a very keen observation. Like in any other branch there are some tough subjects in this one too. But it becomes easy when you spent some time on it. Coming to the job point of view, this is a field where EXPERIENCE is everything. The more experienced you are, the more the salary, more chance of getting into good  MNCs. So the more you age, the better. Placements at college level would be much less compared to other fields. So in the initial days after passing your B.Tech degree you will have to struggle a lot inorder to get a good job. But its worth the effort. Because your hard time would end within three - five years. After that you become a pro in everything and you can get a really high profile job. If you know your job then no one can push you out of this industry.

MECHANICAL

Automobies and other machineries comes with Mech. So if you are someone who was interested in tearing and repairing every single electrical toys when you where young , then this could probably be the field for you.(my brother took mech and he used to be like that.) You can get good jobs in India or in foreign if you have real talent in this field. You can work in  the designing or research departments. Job is somewhat less in India. And in other countries it is hard to get one , unless you have someone to pull the strings there.

ECE,EEE

I personally don't know the exact difference between these two. So I wouldn't comment much on it. Even if you take these two fields your can get job easily in the IT sector. ECE used to be one of the most preffered branch after Mech at the time when I joined for Engineering in 2012.