Hey there

Both of the institutes are very good in terms of placements infrastructure and providing education to the students. It is quite difficult to tell which institute is more better. However for more details related to these two institutes you can click on below link for clarifying and getting your answer:

IIIT Kota

https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.careers360.com/university/indian-institute-of-information-technology-kota/amp&ved=2ahUKEwig6ZK03YPzAhXR9nMBHSXiBbIQFnoECAwQAQ&usg=AOvVaw0K5p82Q-tDCgHwSAedNgFJ&ampcf=1

IIIT Kottayam

https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.careers360.com/university/indian-institute-of-information-technology-kottayam/amp&ved=2ahUKEwi3lJ-_3YPzAhXc7XMBHbPbCc0QFnoECAcQAQ&usg=AOvVaw3oc91jQRz9Wav2Si4YeS9m&ampcf=1