Hello aryan,
Best line for a computer science and engineering Student depends on the interest and the skills that a student have.
Computer science is one of the most diversd field in the engineering. As a student have a lot of ways to choose his career. There are field such as IOT , web development, machine learning, artificial intelligence, data scientist, app development and various others.
One of the most demanding line now a days and in future is artificial intelligence and data science.
                                                The student working in this line have a very bright future and had a very good salary.

Hello,
That totally depends upon your interests!!
Nowadays ,Machine learning and IOT is in most demand and also it is the future .Web designing and app development are also in demand but there are many peoples who are working in these fields.
Think over your skills and choose a field particularly.
Good luck.