Hello Himanshu,

Both are different fields and there are jobs in both the fields. I would suggest you to choose the branch in which you are interested. It depends on your interest, knowledge and skills. One can find jobs in both the fields if they do well.
Some of the job roles for Civil Engineers are- Research, Planning, designing, management of structure.
Construction, installation, and modification of structure, etc.
And, as Computer science engineer, you can work in database management, IT, embedded systems, Telecommunication, computer hardware & software implementation & maintenance, multimedia, web designing, gaming, and almost all other industries in this sector.
So, choose wisely depending on your interest.
Good Luck!