Whether IIT Patna CSE is better or MnC at IIT Guwahati, depends on what you want to do after your graduation. 

If you have an interest in pure and abstract Math and want to do research in Maths, theoretical computer science, Set theory, Group Theory, and Complexity Theory, then the IIT Guwahati MnC program is the best for you.

However, if you have an interest in coding and want to become a competitive programmer, or a software developer, and research in areas other than Theoretical Computer Science, then IIT Patna CSE is the right choice for you. Extensive research on every CS field is done here.

Basically, the academic workload of the MnC program at IIT Guwahati is too much with a very rigid curriculum that will spare you no time to focus on coding. No doubt, the MnC program too has excellent job opportunities in finance, banking, and software jobs. But, the demand for CS students is much more than MnC students and is expected to be increasingly so over the next few years. 

Common courses of CS and MNC include theoretical computer science, some being computer networks, and operating systems while the rest of the courses are related to abstract Maths/pure Math and are highly rigorous in nature. Contrary to popular belief, there aren't many common concepts between MnC and CS. 

IIT Guwahati will give you a slightly better campus life in comparison to IIT Patna considering its scenic campus and high-level fests organized by the institute.

PICT is the best option for CSE in Pune followed by VIT Pune. The faculty pool of PICT stands apart from other colleges making it the dream college of many. I once visited a technical project exhibition in PICT and fell in love with the innovative environment of the college.

The cutoffs are usually high for PICT and it accepts only the best crowd. So you will get an amazing experience if you choose PICT over VIT.

The two primary criteria to evaluate a branch's credibility are academics and job opportunities. 

Academically, NIT Rourkela has a certain advantage over Jamshedpur because it is one of the top NITs. Moreover, the curriculum followed is rigorous and students are expected to maintain a high attendance. The CSE department in particular is very rigid, unlike NIT Jamshedpur which has a laid-back attitude with very lenient professors. It's quite challenging to score high marks at NIT Rourkela CSE especially its Data Structures and Algorithms which is a compulsory course for every branch in the first year. The professors are very passionate and learned so the classroom sessions are quite intuitive. But maintaining a high score may be a problem here so you can go for NIT Jamshedpur.  

Placements: Most software companies don’t visit NIT Rourkela because of its remote location and lack of air connectivity. Here is a comparative analysis of the placement statistics of both NIT Jamshedpur and NIT Rourkela

Talking about CSE placements specifically, NIT Rourkela's average package for CSE is INR 21.87 LPA while NIT Jamshedpur's CSE average package is INR 26.63 LPA. NIT Jamshedpur seems to be a much better option for CSE as it has better placements and also a flexible academic scenario.

I have a cousin who is currently working as a senior software engineer at Walmart. He is anex-student of IGDTUW. This alone negates all the claims of people stating IGDTUW is a below-average institute with poor infrastructure and zero placement opportunities. In fact, the first job he landed with campus placements was at Adobe. His juniors got placed in better companies like Google, Facebook, etc which speaks of the improving placement scenario.

Here is a comparative analysis of the placement scenario of these institutes 

Its true that NIT Calicut may have an upper hand in terms of infrastructure, but in the long run, that does not really matter. A college can give you the wings to fly and it's on you how high you rise. Moreover, being a girl, you will have better opportunities in a girl's college like IGDTUW.

Yes, you will have to make small sacrifices like moving away from your home and adjusting to minimal facilities but in the end, it will be worth it! 

I can only guide you but only you know what is right for you. If you are serious about a career in CS, Thapar University will offer better opportunities and an environment. But if you want to explore other things and also want to enjoy your college life, then taking a dual degree at BITS Pilani will be a great choice for you. BITS has a very flexible curriculum so it allows you to explore your ambitions thoroughly and openly. Moreover, you will be exposed to a better crowd and culture so obviously the learning experience will be more enriched. Generally, both institutes have their pros and cons, and going through these will guide you better toward making a well-informed decision. 

Thapar University Pros: 

1. You will be able to study CS, which has amazing job opportunities.
2. You will complete your graduation in 4 years
3. Excellent accommodation facilities at par with BITS

Thapar University Cons:

1. 75% attendance rule
2. The crowd and academic ambiance are not at par with BITS because of the reservation policy.

BITS Pilani Pros:

1. No compulsory attendance rule
2. The packages offered are great but you will have to work hard for them
3. More talented and skilled peer groups because of no reservation
4. Dynamic campus life

BITS Pilani Cons:

1. You will be completing your graduation in 5 years, a year later than your BTech counterparts
2. You will have to study extraordinarily hard in the first year to get the branch of your choice.
3. Intense competition and academic pressure.

Lastly, don't take dual degrees in BITS on the pretext of getting  CS. Only a handful of students get to choose CS in dual degrees.

I won’t recommend you choose a dual program from BITS. For CSE, I would highly recommend IIIT Delhi. It has great research opportunities. It does not have the same branch value as NSUT Delhi/ DTU, but its growth rate is high. It will soon become a brand like IIIT Hyderabad. Compared to the new IITs, IIITD has a locational advantage because it is situated in the national capital. 

BITS dual is a decent choice, but only if you get a CS. It depends on your performance in the first year. The odds of getting a CS are less than 20% which is pretty low, and the cutoffs keep getting higher each year. As far as the ‘BITS’ tag is concerned, it's really not that important in reality.

For the new IITs, go only if you are getting a CS over there. Do not rely on branch change. Also, avoid going to those located in small/ secluded towns because then you won’t get a lot of exposure. Also, do consider the faculty and infrastructure if you plan to go to a new IIT. My order of preference for CSE is IIITD > NSUT Delhi/DTU > BITS Goa/Hyderabad > IIT.

Thus, for a CSE, I would suggest you to choose either IIITD or NSUT Delhi/DTU.