As you have inquired regarding B schools in Kolkata with a budget of 6 lacs and good placement. I would like to recommend you that in Kolkata you can always inquire BIBS (Bengal Institute of Business Studies) it is located in south Kolkata. So if you check there website you will get to know that the fees structure of BIBS is around 5 lacs. The placement record of BIBS is also very good there students get international placements and also they get opportunity to work with companies like Google, Pwc and many other company. For further details you can also check there website www.bibs.co.in.

I hope I had been of help regarding your query.