i have count my marks for cat response which was around 37 with couting negative marks.and i get only 7 marks in scorecard how can that happened??

There's nothing to worry if you could not do well in CAT. There are several other exams also that you can consider. They can also get you good colleges. May be you did some mistakes.

Moreover the scorecard provides you the scaled scored which is a normalized score which is calculated on a relative basis. So don't worry about that and just prepare well for the upcoming exams.

Good luck