There is no cutoff or merit list in IAT. You are just provided with the information whether you are in or out.  

With this score, you can get some of the new IISERs. Since the allotment generally gets closed at the score of 70.

However, you should also fill the old ones during the choice filling as well.

For more information about IAT, you can go for the below link:

https://engineering.careers360.com/articles/iiser-merit-list-and-cutoff

Best of luck for your future!