IIIT Guwahati seems to be a good option but one must have heard that “All that glitter is not gold”. There are many colleges having people who completed their PhD from IIT. Doing a PhD from an IIT doesn’t make that person a competitive teacher. 

Many of them may have acumen but lack teaching abilities. Very few of them are capable. The course structure is a plus point but still one should not join IIIT Guwahati. It is still not well established plus the factor that makes a college good or bad is the quality of students entering them, and its doubt that the student finds a quality bunch of students there.

The table shows a brief overview of the institution:

If you have a good rank in JEE Main then you can get IT at some of the good NITs. Otherwise, the you have a good chance of getting CSE in the new IITs, and both the options are far better than joining IIIT Guwahati.

One of my closest friends is a student of IIIT Guwahati. Through him, I got to know about the institute. Discussed below is a brief overview of the institute. 

Infrastructure:

• The classes have shifted to a new campus for some time now.
• The institute has a fully functional administrative block. Which is also used as a lecture hall, and is air-conditioned, and has proper Wi-Fi connectivity. Only, the ECE labs have faulty AC.
• Freshers are provided with double sharing rooms with attached bathrooms. After the first year, boys and girls are given single rooms. 
• Faculty of IIIT Guwahati get apartments inside the campus.
• The library of IIIT Guwahati is not at all satisfactory. There are books mostly related to course subjects only. Even the overall collection of books is quite less in number.

Food:

• There is no cafeteria inside the new campus. There is a place for coffee and snacks in the administrative block.
• Hostel mess is not at all decent and takes a lot of time in serving food. The catering service providing food, namely South Coast Catering Service, has not improved with time.

Sports:

• There is no separate gym or sports complex inside the campus. A temporary field and volleyball court are there for students.
• The boys’ hostel has TT table and carrom boards, but none such facilities are present in the girls’ hostel.

Campus Activities:

• The cultural-fest Yuvaan is improving with time and with the growth of student-base and funds.
• There is an E-cell that organizes entrepreneurial meets, on a large scale with a huge budget of around 15 crores.
• There are several clubs for dance, movie, music, quiz, literary, and coding inside the campus.

Faculty:

• The department of CSE, ECE, and mathematics have professors who are Ph.D. from IITs, IISc, ISI, and other top universities. HSS department has PhDs from DU, JNU, and IITs.
• There is no separate set of science faculty, so those subjects are taught by IIT Guwahati science professors.

Curriculum:

• The curriculum is excellent and is entirely industry-need-based, mainly focused on research.
• There are changes in the course every year depending upon the present needs. Students are allowed to make suggestions in modification.

Connectivity:

The campus is situated 4 km away from Guwahati airport and 25 km away from the city center. There are weekly bus shuttles, provided by IIIT Guwahati.

Overall, the points above provide a brief scenario about IIIT Guwahati and the conditions of every aspect related to the institute. A student who is a CSE or ECE aspirant can consider IIIT Guwahati as a good choice.

IIITDM Kancheepuram is an institute of national importance and it has an advantage over the other two institutes as both the institutes are IIITGs in PPP Mode. The bill to declare PPP mode as institutes of national importance is still pending in parliament. 

Here are a few pieces of information about the CSE/IT in the campuses mentioned in the question. 

IIIT Guwahati:

The institute started in the year 2013 and has a strong CS department with a good number of experienced faculties. 

• Prof Gautam Barua who is the director of the CS department at IIIT Guwahati was also the director of IIT Guwahati from 2003-13. With his immense experience, he aims to build the department strong. 
• Coming on to the curriculum of CSE/IT, it is well designed to suit the growing need of the industry. The intent here is to complete all the core subjects in the first 6 semesters so that students can choose the type of industry they want to get into. Like in the 4th semester, there is a subject called Computer Network which is generally a subject of 5/6th semester in other institutes. 
• In the CS department, IIIT Guwahati has come up with the Ph.D. program as well. 
• There are many advantages to join IIIT Guwahati but only a single disadvantage is there i.e. Location. But if you love to travel and nature, Guwahati is a place for you. 

IIIT Sri City: 

• The number of faculties at IIIT Sri City is nearly half as compared to IIIT Guwahati. 
• They also have MS and Ph.D. programs which indicates that they are also very active with regard to research. 
• They are being mentored by Prof. UB Desai who is also the director of IIT Hyderabad and a pioneer in System and Network Research in India. 

Both the colleges have their advantages and disadvantages. You have to analyze which is better for you to pursue B.Tech in CSE/IT as per your parameters. Good luck.