Hi Ani,

This is very easy as you can download it from google directly.

Only thing you have to type in google search engine is "IISER Previous year question paper" and they will show you various sites from where you can download the question directly on .pdf format.Or you can get the some sample papers on the given below links:-

https://engineering.careers360.com/articles/iiser-2016-sample-papers

Hope this will help,please feel free to ask if you have any further queries.

Thank You.