There is nothing like that every subject have there equal waitage and have there different field its depend upon you in which field you are better . But as per seeing toward the placement now days computer science (cs) and electronic communications have better scope there placement cell are better than other courses

Hello dear aspirant
The top college of engineering in terms of placement are the Indian Institute of Technology (IITs) ,  Birla Institute of Technology ( BITS Pilani) ,  Delhi Technical university (DTU),  National Institutes of Technology (NITs),  Indian Institute of Information technology (IIITs).
There are some top private colleges like VIT,  Manipal Institute of Technology and other good colleges which have high placement.
Hope I am clear.