IIT

Under the UGC grading of all the universities, UPES is a A grade university. As here you are comparing from IITs and NIITs definitely it is less. I don't know the exact ranking. But here placement is much better than many private universities like AMITY, MANIPAL, etc. Placement here is quite good.

Only only & only practice can help u a lot.
More & more problems will help in clear the concept & application of formulas.
You should focus on boosting your speed, revise end result, key points of some chapter.

The revised fees for IITs is 2 lacs per year.

University of petroleum and energy studies,dehradun

No only 3% to 5% students of whole 2 lakhs students will get admission and remaining students may opt for local colleges or go for one more try

IIT or abroad both are equally good for master's because you will get a chance to be trained under world's best faculty. If you are looking for a global exposure, go ahead with universities abroad. Check this.
http://www.gsd.harvard.edu/#/academic-programs/master-in-design-studies/