Yes, IIIT Allahabad is also a decent institute, providing a similar graded placement as MNNIT Allahabad. There are several similarities between the two institutes, with some added advantages of being in IIIT Allahabad too. 

The table below gives a brief level of comparison among the two institutes.

Key Highlights:

• The IT department of IIIT Allahabad has a smaller batch size than CSE at MNNIT Allahabad, along with some better lab facilities in the institute.
• The placements in both institutes are more or less the same. Most companies visit both the institutes, both of the institutes being in the same city.
• The coding environment in IIIT Allahabad is much better than in MNNIT Allahabad.
• The subjects in IT at IIIT Allahabad are almost the same as the subjects in CSE, with slight differences in curriculum.
• The labs in IIIT Allahabad are excellently maintained and properly equipped with instruments.

Therefore, IIIT Allahabad is no doubt an excellent institute for IT and the candidate will be in no loss choosing the institute. Other than that, it depends upon the candidate as to how much he/she can put the effort into preparation.

It would be completely wrong in saying that faculty is not good or not well educated. There are only a few teachers who lack spoken English skills. This is probably a great problem for students who do not understand Hindi and are more comfortable with English. If a teacher cannot speak English, it doesn’t mean that he/she is a bad teacher. Teachers anyways have more knowledge than us. 

Each faculty have a lot of potential and capabilities. There are a lot of other aspects in which they outshine. People stuck with a mindset of criticism will never appreciate their teachers, even if they teach well. 

Despite their poor English, they are good at speaking and understanding it and are always ready to help the students in whichever way possible. You can go to the professors and ask your doubts after the lecture is over. The faculty will definitely clear all your doubts, moreover, in English, in the language, you are comfortable in understanding.

All this is just because the mother tongue of most of the teachers and faculty members is Hindi and hence sometimes end up explaining the topic in Hindi. This doesn’t mean the teachers are bad at teaching. 

Firstly, you should know that there is no difference in the facilities and reputation of the colleges, Although BITS ranks better as an engineering school. BITS Pilani ranks #30 on NIRF's Engineering rank list and IIIT Allahabad ranks #103 on the same. But you should focus on your monetary capacity in consonance with your future plans before applying. 

My cousin studied at IIIT A and the following points are based on his experience:

• IIIT A is an excellent place to study coding. The classes are good although the syllabus has to be maneuvered because it's tough. You can manage it through attention in the classroom.
• Attendance is an important part of the academic process here because IIIT A has a 75% mandatory attendance rule.
• Without a doubt, BITS has a higher fee range as compared to IIIT A, about 7 LPA for a 4-year program.

Here's a table comparing both institutes:

Lastly, if you love the mechanical stream and are truly motivated to study Maths and Physics then you must go for it. Mechanical is a vast field as well because you'd learn everything related to mechanical processes and even production scheduling. So clearly check your interests and goals before deciding.

There are no such specific prerequisites. You can develop an interest in coding within one year if you are interested.

The programming courses in the first year entail the comprehensive usage of C. It definitely is an extensive course and will take up time. You will learn the basics of it in the first year. The course includes parts like Functions, Pointers, Linked Lists, Data Structures, Object-Oriented Programming, etc.

Although, having knowledge of Python helps. If, however, you've arrived with no knowledge at all of what that is, then it is fine too. Classroom teaching does not help that much for learning to code. Mostly, you will need to learn the aspects of this language with your own efforts.

If you have any spare time, learning basic front-end web development will assist in the long run as well, like HTML, CSS, JQuery, and Javascript (If possible). This will help explore a variety of other opportunities outside your curriculum.

No, Not at all. The environment of coding at IIIT Allahabad is highly intense because there are a lot of those students who are really fond of coding. But apart from that, there are a lot of those students who are also preparing for other competitive exams as well like CAT/ MAT/GMAT/GRE. Hence, one cannot say in the generalization that IIIT - Allahabad is for coding-lovers only. 

A larger number of alumni from IIIT-Allahabad are in major universities like Stanford University, Carnegie Mellon University which is the best in Computer Science and Research Studies, which proves the above statement. To summarize all this, there are a lot of people who come to the institute because they have that intense zeal of learning coding and they do it very well while there are some other students as well who follow their own passion amid the peer competition and highly pressurized learning environment. 

IIIT Amethi is situated near a village named Tikarmafi, 10 km away from Amethi. It has its own perks. Here are some factors about the institute.

Academics:

• Both IIIT Allahabad and IIIT Amethi have the same curriculum and professors. Because of that, professors visit the Amethi campus on a daily basis. 
• As almost everything is similar for both campuses, the exams are also conducted parallelly in both of them, making them at par for things related to academics.

Placements:

• Students of IIIT Amethi are shifted to the campus of IIIT Allahabad after their 4th year, securing them placements similar to the Allahabad campus. 
• Needless to say, IIIT Allahabad does come with good placements. IIIT Amethi also enjoys the same privilege as placement is same for both the institutes.

Facilities and Infrastructure:

• This is exactly where you can set the contrast between the two campuses. IIIT Amethi lacks good infrastructure. It is a very compressed campus with only two boys’ hostels and one girls’ hostel. 
• There had not been any sports facilities in the institute before. But at present, it has standard Basketball courts, a Badminton court, TT tables and a playground for cricket.
• The labs and libraries are minuscule too. It can hardly support the strength. 
• Besides, you might also not find any up-to-the-mark food items around the campus, but just snacks to keep the day going.
• There’s an option to take a bus ride to visit a town nearby, Sultanpur, which helps in a way to let students escape from the everyday life at Amethi, and rather spend time in that area, or buy decent food.

IIIT Amethi does have its fair share of disadvantages but it offers good placement in top-notch MNCs such as Google, Facebook, and Adobe, etc. Also, the pros outweigh the con for IIIT Amethi.

 If you are given a choice between IIITA and IIITD, take admission in IIIT Delhi hands down. You will never regret it. IIIT Delhi has everything that a good IT institution needs i.e. Great faculty, excellent domestic and international placements, and an overall great experience.

IIIT DELHI

The cut-off for admission at IIITD ranges from 16694-28261. IIITD has a great set of faculty members and the curriculum is excellent.IIITD lacks diversity. With around 85% of the student community belonging to Delhi, it isn't catering to a pan-Indian audience. IIIT-Delhi students seemed frustrated with the workload and students are left with deadlines every single day and thus have no life out of academics. 

IIIT Allahabad

The candidate must have cleared the JEE Mains. The cut off for admission at IIITA ranges from 1291-5330. IIITA has a great coding environment. Faculty is not up to the mark.

They both have a good curriculum but IIIT Delhi has so much more to offer. So If I were you, I would definitely choose IIITD.