The cut off marks for the UPSC CSE are basically the marks secured that the last candidate that was selected for that round.
The cut off marks for UPSC 2021- Prelims and Mains, and final cut off have been released instantly after the declaration of the final result of UPSC CSE 2021. The result came out on 30th May 2022.
Now when it comes to determining the cut off, UPSC has its unique way to calculate.
Only the marks of Paper 1 of the prelims is used to determine the prelims cut off. The marks that you secure in Paper 2 will not be considered when counting your merit ranking. Paper 2 is qualifying in nature and you need to score at least 33 % in it to qualify for the Mains round.