IIIT

When the comparison is between IIITs and IITs, the war is always in favour of IITs whether it be any branch or stream.
The reason being the quality of students, management of IITs, the large-scale organization of events as well as technical and cultural fests from which students learn a lot.
Although, a IIIT may have a better infrastructure due to its late establishment but is overcome by the vibrant lifestyle of IITs.
Now coming to the placement statistics, the average there at IIT Guwahati is around 18 lakh per annum whereas 12 lakh from IIIT Vadodara.
Also, the highest package ever from IIT Guwahati is around 92 lakh in google whereas is 27 lakh from IIITvadodra creating a huge difference between the two.
Now, one may get into IIIT through Mains and through advance in IIT.
Sincerely, there is a lot of hard work needed for getting into CSE for any of the IITs, NITs and IIIT, but the preference should always be given to the IITs than top NITs and then top IIIT. Although some IIITs are working exceptionally well up to the mark of IITs, which are IIIT Hyderabad and IIIT Allahabad.
Thank you. Hope it will help you.

Here are the top IIIT college in India:-
1. Indian Institute of Information Technology, Thiruvananthapuram:
Indian Institute of Information Technology and Management, Thiruvananthapuram (IIITM- K) was established in 2001 located at Thiruvananthapuram, Kerala categorized as IIITs affiliated with University of Kerala and approved by AICTE
2. Indian Institute of Information Technology and Management, Gwalior Gwalior:
Atal Bihari Vajpayee - Indian Institute of Information Technology Management, Gwalior (ABV-IIITM Gwalior) was established in 1997 located at Gwalior, Madhya Pradesh categorized as IIITs affiliated with Rajiv Gandhi Technical University and approved by AICTE
3. Indian Institute of Information Technology, Guwahati Guwahati:
Indian Institute of Information Technology, Guwahati (IIITG) located at Guwahati, Guwahati categorized as IIITs affiliated with and approved by AICTE
4. International Institute of Information Technology, Bhubaneswar Bhubaneswar:
International Institute of Information Technology, Bhubaneswar (IIIT-B) was established in 2006 located at Bhubaneswar, Orissa categorized as IIITs affiliated with Biju Patnaik University of Technology and approved by AICTE
5. International Institute of Information Technology Bangalore:
International Institute of Information Technology, Bangalore (IIIT- B) was established in 1999 located at Bangalore, Karnataka categorized as IIITs affiliated with Visvesvaraya Technological University and approved by AICTE
6.Indian Institute of Information Technology, Allahabad:
Indian Institute of Information Technology, Allahabad (IIT-A) was established in 1999 located at Allahabad, Uttar Pradesh categorized as IIITs affiliated with Allahabad University and approved by AICTE.

There are some good institutes apart from IITs, NITs and IIITs. You can check this list:
https://www.shiksha.com/b-tech/ranking/top-engineering-colleges-in-india/44-2-0-0-0. This list also includes IITs, NITs and IIITs. So, I will mention the colleges other than IITs, NITs and IIITs here:
BITS-Pilani
Indian Institute of Space Science and Technology
Anna University
IIST
DTU-Delhi
NSIT-Delhi
Jadavpur University
BIT Mesra, Ranchi
PSG College of Technology
Institute of Chemical Technology, Mumbai
PEC University of Technology
IIEST, Shibpur
TIET, Patiala
HBTU, Kanpur
College of Engineering, Pune
I am doubtful about these but some rank them higher so I will let you know (I personally believe that you should avoid these colleges)
VIT-Vellore
SRM
Apart from them some good colleges which you can go through JEE or KVPY are:
IISC
IISER
Also, check Indian Institute of Statistical Institute if you are passionate about maths.
All the best.