Are the IIMs at Ahmedabad Bangalore and Calcutta equally good, especially regarding placements?

All three are fantastic brands, but that's it. After the first two terms, there isn't much to learn at any of these colleges. If you come from a CA/Commerce background, you won't need to learn much about these two terms. Case study-based instruction is overrated and out of date.

Because the cultures on the campuses differ slightly, it is best to consider where you will fit in the best.

While the set of recruiters is very similar, your ability to get shortlisted is heavily dependent on your relative profile, i.e., your performance in comparison to other students in your batch. It is more important to consider how good your profile is in comparison to the recruiters who come to the college.

IIMB has a much higher average work experience, and IIMC will have more people with extremely high CAT scores but a slightly lower academic performance history. For example, if you don't have stellar academics and aren't from one of the top undergraduate institutions, IIMC is a better option for placement. If you want to work in finance but don't have much experience, IIMA is probably not the best option for you.

A and B have much more professional placement cells, but C has made changes in recent years to move in this direction as well. However, having a professional placement cell does not guarantee a completely fair process, because, in many companies, PPO holders play a significant role in Summer placement shortlists. However, when compared to other colleges, the situation in these three is far superior.

IIM A is a slightly better brand than IIM B and IIM C, but the difference is not significant. You should talk to people at all of these colleges about placement. While much placement-related data is kept confidential, students can still give you an idea of your chances in the field of your choice.

Rather than following the age-old ABC pattern, make an informed decision.