I have some friends at IIIT Allahabad, so I can give you an idea about the vacations. During the four-month-long semester, IIIT Allahabad offers two vacations. 

• One of these two vacations is a mid-semester break, which usually commences one and a half months after the starting of the semester. The mid-semester break is usually about 6-7 days long. 
• At the end of semesters, there’s also an end semester break. End semester break is usually one month long for odd semesters and two and a half months for even semesters. 

This should give you an idea of the vacations in IIIT Allahabad. You will find more information regarding the same on the official website of the institute.

Business Informatics was chosen by one of my friends at IIIT Allahabad. So, I will be able to share some of his experiences. The course mainly focuses on business and technology domains. The faculty is very helpful and supportive and you feel like home here.

Placements: 

• The branch was established in 2019 which is why there are currently no placement statistics.
• However, you can assume that they are almost the same as IT, because after all, it's an IT branch, and then BI as a specialisation. 
• You don't need to worry about placements, because it's really a worthy discipline.

Cutoffs: If you are in the general category, the cut-off was approximately 7100 according to the last year. Perhaps this year also the cut-off will be similar due to low deviation. The Cut-off stats of 2020 of JEE Mains by NTA are as follows: 

The institute’s course curriculum covers all subjects of the IT branch, plus one additional subject for BI. It will be quite difficult for you to cope up with all the subjects but if you work hard then it will be easier for you.

Among the institutes mentioned, IIIT Allahabad is a better alternative for Bioinformatics. One of my friends was also going through this same situation a few years back and he chose IIIT Allahabad. His experience at the institute has been quite good over the past 4 years. 

The table shows a brief overview of the institutions.

Highlights: 

• IIIT Allahabad is a premier institute renowned for its IT branch. 
• Every year around 85% of students get settled with their dream jobs. 
• BI students also go for IT companies and get placed respectively. 
• Core Bioinformatics companies don't visit the campus usually, but product-based companies like Amazon, Directi, etc offer handsome packages. 

Overall, IIIT Allahabad is the potential choice as the faculty and infrastructure are good and all the previous year’s students have been placed with good packages. 

My brother is currently studying IT at IIIT Allahabad and according to his first-hand experience and your interest in IT, the order of preference for you should be:

IIITA>MNNIT>BITM>MANIT

It is because if you are genuinely interested in IT then IIIT Allahabad is the best option you can choose because of the following key points:

• The campus is well equipped in terms of infrastructure and facilities and the coding culture is quite good there. Also, it is an institute specifically made for IT, so the infrastructure is planned according to it.
• The course structure at IIIT Allahabad is also strikingly different from what you'll find at any other engineering college in India. It focuses a lot on programming and electronics-related subjects, right from the first year itself.

In NITs, you need to study a lot of subjects not at all related to your branch or course!

However, MNNIT or BIT Mesra may prove to be better options in case you realize that computers are not your cup of tea and decide to go into the non-tech sector. You will have a lot of diverse companies visiting these campuses, while in IIIT Allahabad you’ll see only IT companies coming to recruit.

Also, JEE Main rank of all the options you mentioned will differ from each other. So your rank also plays a major role in selection.

If you go through the placement brochure, you will come to know about other significant details such as the campus life, coding culture, and also the placement procedure.

If you look through the official website of IIIT Allahabad, you will come across the following data:

Note that they provide information only about the average salary and the highest salary. There is no information regarding the median salary on the official website.

There is a difference between average salary and median salary. Average salary is the sum of the salaries of all the students divided by the number of students. This includes the highest salary as well and therefore, can be higher. The median salary is the salary that is exactly in the middle of the list of salaries of all the students. Half of the students will be above it and half will be below it. Hence, the average salary is generally higher than the median salary.