isro cut off marks tell me

You can go to ISRO careers section and search for the previous test results. You will get a pdf of last exam results and shortlisted candidates with their marks.
Some stats I collected
For Mechanical(SC-002)
Number of Questions: 80
Total Marks: 234 (2 questions are ruled out)
No of students selected: 295+5(PWD)
Highest mark: 173 (interestingly not selected after interview)
295th mark: 131marks
No. of people shortlisted after interview: 33
33th person average score: 66.16
No.of waitlisted candidates 11