CAT and XAT exams are conducted every year for admission to MBA courses in IIMs and other top Bussiness schools of the country.
Every year around 2-3 lakh students apply for this exam for admission to premiere institutions of the country.
Sucess rate means the number of students passing the exam per 100 students who appear for it.
For CAT the success rate is around 2% i.e around 2 out of every 100 students who appear clear this examination.
However its better to focus on preparation.
Follow this link for more information on CAT and preparation tips
CAT Pathfinder - IIM & Non-IIM MBA Call Predictor
Know Your Calling Chances from IIMs & other Top MBA Colleges, Eligibility & Cut-offs