How to check the cut off when our result is declared? How can we compare our score with others?

All the IIMs usually publish detailed summary of their selection process. Here is one such document for IIMA. You can use this document to estimate how well you did in CAT and what should be your areas of improvements. http://www.iimahd.ernet.in/users/admission/files/Shortlisting Criteria for PGP