If you are doing EC then, I believe, at some point of time you will learn C/C++, Unix and a few other things related to CS in it as well in the form of some subjects in curriculum.
A good Electronic engineer can always look for a job in companies that design chips etc. and these type of jobs tend to pay a very high salary to good engineers. There are many MNCs like
Qualcomm, Texas Instruments, ST Microelectronics, Infineon etc that are doing that kind of work in their development centres in India now a days BUT these companies typically look for engineers from top class institutions like IITs only when they are recruiting freshers.
A CS degree holder may not try for jobs in chip design or electronic components design companies but there are more companies in India that are looking for programmers than there are companies that are looking for engineers for IC design work.
It comes down to this: Are you getting admission in a top class institution (like IIT or Delhi College of Engineering and such) with well established reputation in India as well as abroad? If yes, then go for EC. If you are getting admission in an institution that is not among the top tier institutions, then go for CS because you will find it easy to get a job after completing your degree.
Also, look at the past 2-3 year's placement track record of the institution you are getting in. Which companies have offered jobs in campus interviews and what kind of salaries they were offering to hire candidates from your college? That will tell you a lot about what to do.
PS: I did 3 years diploma in Production Engineering from a polytechnic in Delhi. Completed in 1994 and have been running my own software development
business (catering to overseas clients) since last over 10 years.