Indian Institute of Science Education and Research (IISER) releases a list of applicants who partly qualify for entrance, but didnt get into the college just because there are no more vacancy for such students.
But as far as waiting list (WL) is concerned, it is great to atleast to be in it.
when a selected candidate fails to get into that college, these WL students (acc to their order of eligibilty) are called to get a seat in that college.
This is what waiting list in IISER mean.
I hope my answer was clear.
Feel free to ask any dobts in comments.