What are the cut-off marks in the aptitude test for different IISERs?

A2A There is no cut-off as such for IISER Aptitude test. It solely depends on upon how many seats are available and what is your rank. From my experience, I can tell you if you can do >60% questions correct in this aptitude test, you will probably get selected. Be sure you at least reach up to this mark.

In case your question is about cut-off marks for individual IISERs, that question has no definite short or easy answer. The IISER aptitude test is used to rank/order students from different boards (for whom there is no other available order). The students are then allotted specific IISERs, by following the preference order given by the student in the counselling form. Each IISER will have a limit on its intake (about 200 students this year). So at the point in the allotment when one IISER is "full", a student opting for that IISER would be given the next available preference.