IEM Kolkata ranks higher than HIT Kolkata in various rankings. But when it comes to placement, both the institute have similar placement statistics. An almost similar set of IT mass recruit companies visit both te campuses with the same CTC. 

Here is a brief overview of the IT program offered by the institutes.

If you want a happening campus life go for HIT Kolkata. It has a sprawling campus with good infrastructural facilities. IEM lacks that as it is situated in the heart of the corporate center in Kolkata.