Dear aspirant! According  to  my opinion  iiser  i.e. Indian institute if science education and research  is a national  level examination  .

This exam is conducted by  iiser itself . As it os counted as one of the most decent  college in india . 

For more information  im providing you some site where  you  can find  your last year model paper solutions  and more 

https://admission.aglasem.com

https://physicssolutions.wordpress.com 

And to find more about iiser you can search  it  on website 

www.iisersystem.ac.in

I hope this information will help you in any way .

Thankyou!