Is it better to get job or do M.Tech after B.Tech with CSE?

There are many other options too such as Database management, Big data and data analytics. It depends on your interest basically. And you can always do a job first and then get your post graduation degree.

You can also go for MBA too, if you are more interested in management side of IT industry.

I think, you should pursue M.Tech with CSE only. Because, now a days B.Tech and M.Tech are common. In my opinion, one should at least complete it's post-graduation also. If you pursue M.Tech, then you have more scope in industries and have a better opportunity than those who have graduation degree a

It totally depends on your mood that you have a strong desire to study or strong burning desire to get a good placement. But, if you don't get good package, then apply for M.Tech. After M.Tech, you are guaranteed get a good placement.