First of all, to clear any misconceptions, IIITH, IIITD and IIITA are not connected in any manner. Out of the three, only IIIT Allahabad is a member of the actual collective known as the IIITs. 

The common public doesn’t know much about these prestigious colleges. Consequently, they aren’t valued as much as the IITs and NITs. Here are the reasons why-

1. All these institutes offer very few branches, which are mostly IT related.
2. They aren’t as old as some of the IITs and NITs. They were set up even after IIT Guwahati, which is the 7th IIT in terms of establishment year.
3. They don’t possess big campuses and a vast infrastructure.

But those who belong to the field of engineering (especially IT), give high ratings to these institutions, especially IIIT Hyderabad. These three offer research oriented academics. They even offer UG research programs. 

IIIT Hyderabad, Delhi and Allahabad are performing really well in their respective fields. They should be given much more attention.

IIIT Hyderabad and IIIT Ahmedabad are the best IIITs and have similar ages. IIIT Hyderabad fairs are better than IIIT Ahmedabad in terms of its coding culture and the kind of job opportunities it provides. 

IIIT Hyderabad students must work extra hard and wake up very early for PT. The institute has a record of attracting a better crowd because a lot accepts only top rankers of JEE Main. One of the drawbacks of the institute is that it’s private and therefore charges hefty fees while IIIT Ahmedabad is a government college so it charges lesser fees. 

IIIT Ahmedabad has a bit flexible campus life quite similar to other government colleges like IIT and NITs. Additionally, it also has a rich coding culture with amazing job opportunities.

I don’t find any major differences in the curriculum, campus life, and placement scenario of both the institutes so choose the one that aligns with your preferences. As for choosing one between IIIT Allahabad and NIT Rourkela, go for the former without any second thoughts. IIITs are best suited for coding lovers and people passionate about computers. So if you are one of them, go for any IIIT between these two!

If you are considering IIIT Bangalore and IIIT Allahabad for your undergraduate studies in computer science and information technology, there are several factors you should take into account before making a decision.

• IIIT Bangalore offers an iMtech program combining bachelor's and master's degrees in computer science and engineering, while IIIT Allahabad offers a bachelor's program in information technology that can later be converted to a master's degree.
• IIITA is a government institute, while IIITB is based on a public-private partnership model.
• IIITA has a larger campus and lower fees, while IIITB has better-credentialed faculty and no reservations of any kind.
• Both institutes have great infrastructure, excellent placement records, and coding cultures, but IIITB has a higher ratio of students qualifying for the Google Summer of Code.
• IIITB is located in the heart of Electronic City, which houses major companies such as Siemens, HP, Infosys, and HCL, providing ample opportunities for internships and exposure.
• The course structure at IIITB is more rigorous, and the peer group is stronger due to no reservations. The focus is primarily on academics and coding, with secondary attention given to sports and cultural activities.
• IIIT Allahabad's course structure is less rigorous due to a mixed peer group. The student community focuses more on extracurricular activities in addition to academics and coding.
• IIIT Allahabad has a lower cutoff for admissions and more seats, resulting in a more diverse peer group.
• IIIT Allahabad has lower fees and is located in a city with a rich cultural heritage.

Before making a decision, it is essential to weigh the pros and cons of both institutes and determine which factors are most important to you. Consider factors such as city connect, peer group, course structure, focus on academics or extracurricular activities, and the environment that would help you thrive. With careful consideration, you can choose the institute that is the best fit for you and your goals.

When it comes to IIITs, IIIT Hyderabad is by far the BEST. IIIT Bangalore is good as well and has some good faculty, but it doesn't have the fire brand in CS that IIIT Hyderabad does. If you're looking for an advantage, IIIT B is located in Bangalore, but then again, IIIT H is located in Hyderabad, so it's not as good as IIIT H.

IIIT D and IIIT A are both government-run and have a 50% reservation. This puts them behind the above mentioned colleges. IIIT D has better faculty and is located in Delhi, which gives it a certain location advantage. However, IIIT A is an older institute. Both places are filled with Delhiwalas and UP bhai log, which doesn't help them either.

If you're a North Indian, you might like IIIT A/D more than IIIT B, and vice versa. However, almost all Indians like Hyderabad as a city. The majority of people in Hyderabad are friendly and know Hindi, so North Indians find it easier to adjust. At the same time, Hyderabad people are not language chauvinists like other South Indians (read Tamilians and Kannadigas), so that also helps. Plus, if you're a South Indian, you will easily adjust to Hyderabad since it still has a Southern Vibe to it.

In short, IIIT H is the best among the above depending on faculty/location/college life and the general atmosphere. If you're not getting IIIT H, you could try for the Top NITs (only Trichy, Warangal, and Surathkal) and then your famous state colleges like NSIT/DTU for Delhiites, Anna for Tamilians, Jadavpur for Bengalis, COEP for Marathis, etc., JNTU, etc.

Here is the answer to your query-

The first ‘I’ in IIIT Hyderabad stands for ‘International’. It is a private ICT Research University that was founded in 1998. The first ‘I’ in IIIT Delhi stands for ‘Indrasprastha’. It is a government institute and comes under the Delhi Government. The first ‘I’ of IIIT Allahabad stands for ‘Indian’. IIITA and IIIT Pune come under the collective of institutes that are actually the IIITs, as in, the Indian Institutes of Information Technology.

IIIT Allahabad is one of the 5 IIITs that were formed by MoE, and it has the tag ‘Institute of National Importance’. IIIT Pune is among the other 20 IIITs that were formed under the PPP (Public Private Partnership) model. It is also an Institute of National Importance.

IIIT Hyderabad is one of the best in India for CS. The CS department of IIITH boasts of top-notch placements, a good number of entrants into GSoC, and high participation rates in Competitive Programming. 

Only IIIT Allahabad and IIIT Pune belong to the collective of Indian Institutes of Information Technology. The other institutions mentioned by you are different from this group.