ISI Kolkata does not provide a B.Math program. The majority of B.Stat students return for M.Stat while some people join CMI, TIFR, IIM, and other such organizations. 

M.Stat employees earn an average of 16–17 LPA, and many of them attend prestigious US graduate institutions. There are no fees for the entire program, and a stipend is provided. So, if you're looking for a career here, your future is bright.

I am not fully aware of IITs courses but could still try to give some insight of the same on whatever I got to know from the internet. 

• The ISI M.Tech CS entrance exam includes an optional Objective Paper Mathematics and a Subjective Paper (you may choose CS).
• The majority of ISI's placements are in analytics firms so it would be advised to not choose ISI if you're looking for a core CS job.
• If you are interested in Algorithm Design, Machine Learning, and, most importantly, Cryptography, then ISI would be a good option. 
• After completing your MTech CS at ISI, you will have several research opportunities in ISI and also abroad.
• ISI has excellent theoretical CS faculty (Mathematics, Statistics, Cryptography, Machine Learning, Data Science). 
• So, if you're interested in learning more about these topics, you can come to ISI.

Please do not expect to find Developer, Coder, or Core CS work at ISI after completing your M.Tech. Students have a misconception about it and come here with high hopes which ultimately backfires.

My brother is doing his PGDBA from IIT KGP and he was rather afraid of programming and coding when he started the course. If you're stuck in the same situation, then my only advice is to enroll in the course with an open mind and a desire to learn to program if you don't already know-how. 

Coding Experience: There is always a first time of everything. Now there are numerous MOOCs available online that can assist you in taking the initial step. The discipline of analytics (technical side) necessitates solid coding abilities, and therefore if you want to pursue a career in analytics, you should start learning the necessary skills now.

Work Experience: It is not necessary to have prior work experience to enroll in the course. However, relevant analytical experience aids in extracting greater value from the course. 

According to your assessment of your interests, you have a preference for fields involving mathematics and statistics. Analytical science is an excellent fit in that regard. I would recommend that you go into MOOCs like Coursera, audacity, and your willingness to learn more about this field. You will obtain a better understanding of the field and would be able to decide if this is a good fit for you or not.

My brother prepared for the Written Examination only in a week and scored close to 110 out of 150. 

Since my brother had a background in Semi-automated Trading, the interviewers were convinced about his love of Finance and Maths. He got waitlisted in 5 of the General Category lists and declined admission after the results.

If you are good at JEE Maths and have contributed to the field, it is important to show your passion to the interviewers. 

Kolkata is one of India's safest cities. This city attracts visitors from all over India and the world. That's why it's known as the "City of Joy." Bengalis are extremely friendly. 

ISI Kolkata is known to have the most sought-after institute in Statistical expertise. It has one of the best faculty members in India. Out of which, 30 professors were published in Standford University.

Moreover, you have got a seat in B.Stat which is considered one of the toughest examinations for Mathematics in Asia. You should base your judgement on the basis of a stereotype as letting go of this opportunity will be a wrong decision.

Almost 50% of the batch consists of Non-Bengalis here at ISI Kolkata. There is no need to worry as the institute also has a rigid anti-ragging policy.

One of my friends is currently in his first year of M.tech CS at ISI Kolkata. Here are some crucial insights regarding the academics and placements according to his experience.

Academics: 

• If you have a CS background in your under graduation too, then all subjects in the first year will be mostly repetition for you. You can also check the exact list on the ISI website. However, many people with a CS background say that they have learned things in a much-refined way.
• In the second year, you finally get to choose subjects based on your interest which will help you in your final thesis.
• ISI is quite famous for cryptography but you can also find good thesis projects in prestigious fields like Machine learning, Image processing, Algorithms, VLSI, cognitive science, etc. Also, you get good guidance in all of these.

Placements:

ISI is particularly famous for statistics. So, most companies coming for placements offer Data science profiles. Very few companies would be offering developer job roles. So regarding the placements, it’s the best place to grab data scientist roles with lucrative packages. In the recent placement highlights, the average and highest CTC offered was 19.80 LPA and 42 LPA. 

Overall, ISI Kolkata is an amazing place to pursue your M.Tech in CS. The great academics and placement record indeed make it a haven for students associated with CS, mathematics, and statistics fields.