Yahoo Bangalore is pretty much a waste of time. The recruitment team does not have the common human decency to inform you of the outcome of the interview.
Interviewers are a mixed bag: some are very professional and some are just bad.
If you have time, go and take the interview for practice or entertainment.
If you get a offer, you have to decide whether to get involved with a company that is on the way out.
Overall, I did not get a good feeling from Yahoo Bangalore. The recruiter and some interviewers were unprofessional.