Design Entrance Exam

It depends on every academic year. Like for stats. In 2008-2009 batch, it was a bad time. Packages were meagre and enough to render you as "salaried " person. It was the recession time than in the year 2012 (my passing out the year). So-called "good" packages ranged from 4- 4.75 LPA. Madura Lifestyle was paying those salaries then the following year saw a better footfall of good companies. For instance, Trident Industries paid the highest package of 9 LPA. And now again in 2015 passing out batches have bagged some good packages from many startups and biggies like Flipkart and Snapdeal. Now that apparel as a category is a serious player in the fortune of these e-commerce sites. They have now started recruiting students from NIFT campuses. A rather welcome change. So if it's an undergrad course, expect a good salary in the range of 5.5-7 LPA and if it's a Master's degree course then you can get up to 11 LPA.
Hope this helps.

Do, absolutely, go for it. It is much better than going for an MBA (unless the MBA serves a grand plan of yours). With an M.Des in hand, sooner or later you'll find yourself wanted badly by the industry. The Indian manufacturing/services mindset is changing, and we are moving towards more of a 'build a brand' mindset. The things that'd get us there are:
a) Greatly designed products and services
b) Great marketing
A design course would not just give you the skills that the industry needs, but also a way of thinking that unlocks doors.
I personally have not gone for a Master's degree after Bachelors in engineering, but being in touch with designers has made me hold them in high respect.
For entrepreneurs:
Design thinking makes you see opportunities, and that's great for an entrepreneurial mind.
For professionals:
The pay may be low (though that's changing too), but some of the projects you might be on will have a potentially great impact.
That said, it's really hard work being a designer if you're up for it and for a prolonged period of struggle, a world of wonder awaits you.