Hello Mr. Perfect , Yes IBS kolkata is a prestigious and successfully recognized college for MBA . It has  great placement record with high growth capacity for students , plus knowledgable  faculties for problem solving . 

You can surely go for it .

IBS is one of the tops b-school in Kolkata which last year had 100% placement of 63 students with an average package of 5.68 lakhs per annum and highest domestic package at 6.75 lakhs per annum. In terms of ranking, it has been ranked as17th All India by Silicon India,  2nd in Eastern Zone by Silicon India, 11th among Top New Generation B-Schools and 2nd among Zone wise – Digital Mailers and 2nd in West Bengal and 4th in Eastern Region among B-Schools of excellence by CSR GHRDC. In terms of infrastructure also it has quite a lot modern facilities along with basic needs like Modern audio-visual teaching aids. And finally, with experienced faculty, it is an overall good college.

IN IISWBM Kolkata out of 98 students, 94 students were placed last year with an average package of 6 lakhs per annum, a median package at 5.5 lakhs per annum and highest package offered as 7.75 lakhs per annum. With established infrastructure, library facilities and good faculties this is also an overall good college.

Both are equally rated college you can go for any of the two colleges. In my opinion, you should go for IISWBM as it is a little more established college but still, it is all your call as IBS is also growing rapidly and has been rated very well.

All the best!!