How can you find an internship in IISc bangalore with a Bachelors degree in Electronics and Communication?

The three national academies of science have a really good program to encourage research among students and teachers. You'd be able to spend a few months at institutions like the IITs and IISc tackling interesting problems in an area you're interested in. Students usually apply around November/December every year. Last year's application portal can be found http://web-japps.ias.ac.in:8080/fellowship2013/. You will have better chances of getting selected if you have a decent GPA and letter of recommendation. Unlike internship programs at certain IITs, they don't blindly use GPA based cut-offs. Your entire application matters. This fellowship is generally considered to be very prestigious and you will also have plenty of opportunities to network with other students and researchers. If you're intelligent and work hard during your internship, you might even end up publishing your work in a respectable journal/conference. Source: I've completed an internship at IISc through this program. It turned my career around.

I would recommend http://internlelo.com/index.php. It's a really great site that cuts across all fields of education, providing information about internships in a very organized manner. Moreover, it's developed by IITians and so you can guess it's pretty good. It is regularly updated and has opportunities for all.

You can mail professors about the possibility of internships under their guidance. or, Contact some students who gets internship notifications in their institutional mail and ask them to notify you whenever something becomes available.