The competition to get into NLSIU is very high due to the merit-based system and they have equally impressive placements. IIT Kharagpur, on the other hand, has a very high number of graduates each year, but they do not get offers as high as NLSIU.

But you should be considering which of these colleges would add more value to you. Even if you choose to do an LLB from IIT Kharagpur, you should know that it is the first premier institute for engineering. Whereas NLSIU is one of the best universities in the country for law. 

Do not choose a college just because it has better placement, instead focus on which college is better for your career in law. A degree from NLSIU would always hold a better position than a degree in Law from an IIT. 

There are so many people that drop out of college just because they failed to research better about their career path and what was good for them.