The newer Indian Institutes of Technology (IITs) like Patna, Indore, and Jodhpur are generally less preferred by students compared to the older, more established IITs due to the following reasons:

1. Brand recognition: The older IITs have a strong reputation and are more widely recognized, unlike the new IITs.
2. Alumni network: Older IITs have a strong alumni network that can provide better placement opportunities and industry connections. This is lacking a bit in the new IITs.
3. Infrastructure: Newer IITs may still be developing their infrastructure, including laboratories, research facilities, and campus amenities.
4. Research opportunities: Older IITs typically have more research collaborations, funding, and ongoing projects, providing better research opportunities for students.
5. Industry partnerships: Established IITs often have stronger ties with industries, leading to better internship and placement opportunities.
6. Placement records: The track record of placements and average salary packages are stronger for the older IITs.

Here is the comparison of the new IITs with an older one (IIT Madras):

Even though IIT Patna/Indore/Jodhpur are not as good as IIT Madras/Bombay/Delhi, they are continuously progressing. As a result, these new IITs are establishing their own place for higher studies. 

I am a second year B.Tech CSE student at IIT Patna. Here is a comparison between MNC at IIT Guwahati and CSE at IIT Patna:

IIT Patna’s CSE has better placement opportunities than IIT Guwahati’s Mathematics and Computing. Moreover, IIT Patna offers many clubs and societies for its students. These include- 

• RnA or Robotics and Aviation Club of IIT Patna. It is a newly formed club that focuses on drones, MAVs (Micro air Vehicles), and aviation robotics.
•  NJACK is the Computer Science Club of IIT PATNA. Other technical clubs/societies at IIT Patna include: AI-NLP-ML Group, DSC and OWASP. 

Thus, because of its good placements and a plethora of clubs/societies, I would recommend you to choose CSE at IIT Patna over Mathematics and Computing at IIT Guwahati. 

All the three institutions mentioned by you are well-reputed for their engineering courses. Here is a comparison among the three based on different criteria:

IIT Warangal is a much older institution, however, IIT Patna offers some very interesting clubs and societies in various areas. Other than NJAC, it offers technical societies like AI-NLP-ML Group, DSC and OWASP. This makes for a healthy coding environment.

Other than that, its highest and average placement packages are also better than the other two institutions. IIT Patna carries the prestigious ‘IIT’ tag which is beneficial when applying for higher studies abroad. Moreover, IIT Mandi has a beautiful but remote location in the mountains. Whereas, Patna city offers better connectivity.

Because of all these reasons, IIT Patna is a better choice than IIT Mandi and NIT Warangal. 

IIT Warangal is a much older institution, however, IIT Patna offers some very interesting clubs and societies in various areas. Other than NJAC, it offers technical societies like AI-NLP-ML Group, DSC and OWASP. This makes for a healthy coding environment.

Other than that, its highest and average placemThe coding culture at IIT Mandi, IIT Patna, and IIT (ISM) Dhanbad is generally strong, as is typical for IITs. However, each institution has its own unique characteristics:

IIT Mandi:

• Active coding clubs and regularly organised hackathons are a part of IIT Mandi’s coding culture. Some of the technical societies of IIT mandi are- The Programming Club (Kamand Prompt) , S.A.I.C., and the Google Developer Student Clubs (GDSC).
• IIT Mandi emphasises practical application of coding skills of the students.
• The institute has a growing reputation in areas like AI and machine learning.

IIT Patna:

• It organises regular coding competitions and events.
• IIT Patna emphasis on both theoretical and practical aspects of coding.
• The students of IIT Patna actively take part in national and international coding contests on platforms like Codechef, Hackerrank, etc.
• The institution regularly organises coding workshops and coding-related events.
• Celesta is the tech fest of IIT Patna.
• NJACK  is the Computer Science Club of IIT Patna. Other technical clubs at IIT Patna include:  AI-NLP-ML Group, DSC and OWASP. 

IIT (ISM) Dhanbad:

• IIT Dhanbad has a well-established coding community.
• It conducts regular coding workshops and seminars for its students.

IIT Dhanbad is mainly known for its strong industry connections in the mining and petroleum sectors. As a result, it has a better learning environment and more opportunities in mining and related branches. 

For a strong coding culture, you can opt for either IIT Mandi or IIT Patna. 

When comparing ISM (IIT) Dhanbad and IIT Patna, there are compelling reasons to favour the latter in terms of a better campus life. These reasons are-

• IIT Patna boasts a newer and more modern campus with state-of-the-art facilities and infrastructure.
• Patna is a larger city, offering diverse cultural experiences and more entertainment options. 
• Some of the clubs of IIT patna are-

1.  NJACK (Computer Science Club),
2. SPARKONICS (Electrical Engineering Club)
3. SCME (Mechanical Engineering Society)
4. Robotics Club
5. IITP Motorsports
6. ACE (Civil Engineering Society)
7. CHESSx (Chemical Engineering Society)
8. MatES (Materials Engineering Society)

• IIT Patna offers a good balance between academics and extracurricular activities, promoting overall student development. ‘Anwesha’ is the Annual cultural fest of IIT Patna. ‘Celesta’ is the tech fest of IIT Patna.

Here are some fun pics from ‘Anwesha’-

Because of these reasons, IIT Patna has a more dynamic and engaging campus life as compared to IIT Dhanbad.

According to me, opting for CSE at 2nd generation IITs like IIT Patna is a better option.  IIT Patna was established as a full-fledged IIT in 2008. Although comparatively newer, it has already created a huge impact in terms of placements and research. 

• The CSE department of IIT Patna is excellent. The course offers good placements and faculty. The course curriculum of CSE at IIT Patna follows leaders in this domain like Harvard, IISc and IIT Bombay.
• NJACK is the Computer Science Club of IIT Patna. It conducts workshops, events and competitions to boost the coding culture and knowledge of computer technology among the students. Some other clubs/societies at IIT Patna are- TINKERER’S LAB, AI-NLP-ML Group, DSC, OWASP, and many more. 
• IIT Patna labs are equipped with a Data-Center which has AI-GPU clusters. There are various labs at IIT Patna such as AI+ML+NLP Lab, Blockchain Lab, IoT Lab, Network Security Lab, Advanced Computing Lab, and Metaverse. 

Here are the 2023 placement details for CSE branch at IIT Patna:

Thus, I would recommend you choose CSE at IIT Patna over Mechanical at one of the topmost IITs.