Hello Aspirant,

XAT is considered to be tough compared to other MBA exams  . Its scoring pattern of +1 mark for each correct answer and -0.25 mark negative marking makes it difficult to score beyond 35-40 marks.It is difficult to predict the exact percentile as it depends on the number of people who qualify the exam and the marks everyone score. This is the approximate percentile score, according to the raw score range ,based on previous trends.So as per this assumption , 15 marks would give you a percetile score of around 50-60 approximately.Please not that it just an approximation and not an exact prediction.

Raw score  Percentile (Approx.)

27-28                   89

29-30                   90+

31-32                   93

33-34                   95

39-40.5                99+

https://bschool.careers360.com/articles/xat-score-vs-percentile

https://bschool.careers360.com/articles/xat-cutoff

https://news.careers360.com/xat-2021-how-calculate-marks-scores-and-percentile

All the best