Each branches are good and have scope in its own field. It depends on your interest & capability.
CSE: Computer science engineers are involved in many aspects of computing, from the design of individual microprocessors, personal computers and supercomputers to circuit designing and writing software that powers them. Job openings for Software professionals is much higher in the corporate sector than in public sector. Professionals can join as junior programmer, database administrator, junior network manager, Data Analyst etc.
ECE: ECE is one of the most popular branches. You can work as an engineer, choose research while pursuing your post graduation. ECE students get placed in IT firms also. PSU recruitment for ECE students is also huge. An electronic engineer can find a job in Consumer electronics manufacturing organization, Telecommunication & IT industries, Internet technologies, Power Electronics, and other industries like steel, petroleum and chemical industry.
It totally depends on your interest as both of them are top branches for higher studies and placement.CSE is preferred more over ECE as there is more opportunities.But you should go for s branch in which you are interested.