Hello there. Hope you are doing good. I would like to tell you that both the exams are quite competitive but if we talk about comparison between the two, then CAT is considered to be much more difficult than XAT. The number of students appearing for CAT is higher than XAT, hence the cutoff his also high. CAT is accepted in more number of colleges than colleges accepting XAT.

At last it depends on an individual, since the exam pattern is almost same, a candidate may be able to perform better in CAT rather than XAT, it all depends on individual's attempt.

I hope you found this answer helpful. Good luck for your future.