I have a few friends from Ravenshaw University and according to them, for M.Sc Science subjects like PCMB, there are no placements. You will have to seek job opportunities on your own. But for other streams, some recruiting companies like Wipro, Infosys, etc. visit the campus. For management subjects also, you will get decent placement opportunities in the campus drive.
According to the recent placement highlights, the overall placement average for Ravenshaw was 70%. The average and highest CTC offered in the placement was 12 LPA and 6 LPA.