A side by side comparison of both the colleges might help you get a clear view on what to expect once you get there:

• Curriculum: The curriculum mentor of IIIT Kottayam is IIIT Hyderabad which is one of the top-notch institutes for CSE in India. On the other hand, the curriculum mentor of IIIT Bhopal is MANIT Bhopal which doesn’t match the level of IIIT Hyderabad.
• Closing rank: In 2019, the closing rank for IIIT Bhopal IT was around 41K in the special round. While for IIIT Kottayam CSE, the closing rank was almost 40K at the end of special round-II. You can check the opening and closing ranks for both the colleges in the year 2019 below:

• Placements: In 2019, the first placement was held where good companies came forward for recruitment. Some of them wereNISSAN, L&T, Reliance (JIO), etc. NISSAN offered packages starting from 6 Lakh to 10 Lakh.
• Coding culture: Coding culture at IIIT Kottayam is at par with old IIIT’s like IIIT Allahabad, Gwalior, and good NITs. More than 70% of students clearing the starting round of CODE JAM conducted by Google
• Campus: While IIIT Bhopal campus construction is yet to be started IIIT Kottayam campus is almost ready.

From the above comparison, it’s pretty clear that IIIT Kotayyam has an edge over IIIT Bhopal. However, do consider your pool of interest because at the end your skills and hard work matters the most for shaping your future!

Between the options, you should choose NIT Surathkal IT. Here are the reasons why. 

• The syllabus difference between IT and CSE is not so much in this institute.
• The placement process in the institute is exceptional, specifically for the circuit branches, including IT, CSE, ECE, and EEE. However, in the last year, students are recruited by Google and Microsoft.
• NITK has its own brand name. Maybe it is an NIT, but the students here get a lot of exposure. JEE Mains toppers mainly take admission in this institute every year.

Here is a full overview of NIT Surathkal

You will have to stay here in the hostel, which provides a good experience for them. During the tenure of the course, you will learn how to take care of yourself. Also, if your hometown is Bangalore, then you can frequently visit home.

My younger sister has enrolled in the CSE program at NIT and it has excellent facilities for the program. The brand name of NIT and IIT is still more popular for some of the engineering aspirants because they lack awareness. Even my sister thought so before admissions, but NIT ranks #16 on the NIRF Engineering scale, IIIT A ranks #103, and IITs are usually in the top 5 in the same. 

Furthermore, your decision may change based on the following-

• The location of IIIT Allahabad is a factor contributing to its low popularity. It is located in a small village area called Jhalwa. There are no recreational facilities around and the only eating outlets are MacDonald's and Dominoes, which harm in the long run.
• The placement statistics of IIIT A show that it has a good 96% placement rate, but not many top companies come to visit because of the location. Networking is not an issue, but an institute in a developed area would have easy accessibility, lectures by renowned faculty, spots of refreshment; which are not present here.
• The hostels are not very good and those who reside in them, face difficulties related to social outings.
• Another fact of importance is that this institute has only two departments: Information Technology and Electronics and Communication.

You can see below, the comparatives of the institutes:

As you may see, IIIT A and NITs have excellent placement rates. The faculty will be more brilliant at IITs but students are dissatisfied even there. So you can see for yourself according to location, placement scenario, and brand name if that matters.

Well that is neither difficult nor simple. It actually primarily depends on how many students are opting for IT in IIIT Allahabad. It is almost impossible to guess what the cut-offs are going to be. Although there is a tough competition among students who wish to go for IT from ECE and you will have to clear that successfully.

How many students in your year are wishing to transfer from IT to EC will also matter in this aspect. Hence, rather than planning and thinking about what the cut off will be, the only thing that you should be doing is working very hard to score the best CGPA in your batch because only that is in your hands. Scoring CGPA above 9 makes it very easy for you to transfer from ECE to IT in IIIT Allahabad.

Obviously you should have all the basic knowledge and understanding such as C, C++, Java etc. before you think of switching your branch.