You need to understand one thing that whether it is a CAT exam or a XAT exam, it is always unpredictive and there are no fixed marks for a certain percentile. As CAT and XAT, both are evaluated on the percentile, not on percentage so it depends on both your performance and also the performance of your colleagues giving the same exam. The marks vs percentile range vary every year.

But still, on the basis of past few year records, we can see that to get 90 percentile marks you need to aim to get around 28-30 marks out of 72. Last year at 29 marks student got 90 percentile which increased to 94 percentile with 34 marks. But as I have said earlier its all a relative game so better to focus on your scores or the predictive percentile through an online mock test which will give a better overview of your performance.

As very less time is left for the XAT exam so you need to brush up on your basics and start giving lots of online mock test and analyse solutions of each one of the thoroughly which will help you in overcoming your mistakes and come up with a strategy to definitely improve your marks and percentile. It will also help you to know about your strength and weakness which will help you in attempting easy questions first, that will reduce your chance of committing a silly mistake in an easy question or missing out an easy question. Along with this, you will also get enough time to attempt medium level difficult questions which will overall increase your speed with accuracy which leads to increase your percentile.

All the best!!