Choosing a college and a program can be a difficult decision. Both IIT Mandi and IIIT Hyderabad have strong computer science programs. However, there are a few key differences that you may want to consider when making your decision. 

• IIT Mandi is a public engineering institution located in Himachal Pradesh, India whereas IIT Hyderabad is a private research university located in Telangana, India.
• IIT Mandi was established in 2009 and offers undergraduate and graduate programs in various engineering disciplines, including computer science whereas IIT Hyderabad was established in 1998 and offers undergraduate, graduate, and doctoral programs in various areas of computer science and engineering. 

No matter how many people tell you that the IIT tag does not matter, don’t believe them. In reality, the IIT tag does carry a certain weight. Additionally, IIT Mandi has managed to make its own good name through constant improvement. 

• The campus is located in a beautiful and serene environment, 
• IIT Mandi Institute is known for its strong emphasis on research and innovation. 
• The CS department of IIT Mandi has a great faculty pool.
• The placements of the CS department are very promising and it is the highest recruiting branch of the institute.
• The only drawback is that IIT Mandi infrastructure and urban life are not at par with other IITs.

Here is a general comparison of placement statics of both the institutes' 

I can never stop emphasizing this, no matter how many options you have always go for the one that gives you the IIT tag.

 I am not saying Engineering colleges like NSIT and DTU aren’t good but they are in the developing phase while IIT Jodhpur is in its developing phase. This means it will only get better. Despite being a new IIT, its average package this year was recorded at INR 21.30 LPA, which is a great feat for a new college. 

Additionally, IITs receive more funding from the government to provide better research and project opportunities. Specifically speaking about CSE, this year the highest INR 56 LPA was bagged by BTech CSE. The placement percentage stood at 97% while the average package for CSE was recorded at INR 23 LPA. 

DTU and NSIT may have higher placement statistics but they lack what IIT Jodhpur offers, the most coveted IIT tag! So choose wisely.

In my opinion, if you are getting a top NIT, then choosing CSE will be a better decision unless you are interested in any other specific branch. As far as comparing the CSE branch in Warangal and Surathkal, both offer similar opportunities and academic experience. 

Given all the similarities, choosing one between these two NITs depends more on your personal choices such as proximity to home and crowd. If you are from the home state of Karnataka choose Surathkal but if you are from the home state of Warangal, choose NIT Warangal.

I would recommend you to go for NIT Warangal as it has better opportunities if you are inclined towards research. The alumni base is huge and there is even an innovation garage where the ideas of students are implemented. 

You seemed to have performed quite well considering your JEE rank and BITSAT score. While most board toppers fail to do well in competitive exams, you managed to excellently score well in all competitive exams. You seem to have great opportunities ahead if you join BITS Pilani, Pilani Campus, and CSE. considering your ranks and your being a board topper, you can easily maintain an 8 +. The only major drawback is the high fees for which you can seek assistance from the institute regarding scholarships. 

Here are a few pros of BITS Pilani CSE

• Top-notch placements
• Excellent exposure
• A flexible college life with responsibilities

If you face serious financial issues and are unable to get BITS, don't lose hope as other colleges offer great opportunities too. The best way to determine the worth of an institute is to evaluate it on the basis of fees, placements, campus life, and academic and professional exposure. Analyze your preferences and go for the institute that satisfies your preferences the most. 

It's difficult for me to say whether choosing IIT Guwahati CSE over IIT Varanasi CSE was a mistake without more information about your specific circumstances and goals. Both IIT Guwahati and IIT Varanasi are highly respected institutions, and both offer strong Computer Science programs that are rightly comparable in almost every aspect.

The placement scenario is similarly decent at both institutes with very little emphasis on research. The active Coding Club/ CSEA at IIT Guwahati gives it a slight edge over others. Both the institutes are excellent choices for whatever you want to do after graduation be it research, open source development, or a stable job.

The only distinguishing feature is the weather as IIT Guwahati has better weather conditions than IIT BHU. However, this flaw is compensated by better connectivity of Varanasi being on the mainland.