Hello Susmit Som, 

                           With a score of 119(out of 180) in IISER Aptitude test(IAT), you do have good chances of getting a seat in IISER Kolkata. If not the first round, you can get a seat in IISER Kolakata in further rouds of allotment.

For further details regarding IISER Kolkata, visit: https://www.careers360.com/university/indian-institute-of-science-education-and-research-kolkata

Hope it helps!

Best Wishes.