Hello student, in your questions you have not mentioned the other two sections marks. So it is difficult to  predict the percentile. According to your questions inwhich  you have mentioned  only 8.23 marks for three sections  is not sufficient for predicting the percentile.

You should have to clear all the details  in your question.

In XAT you have got 8.23 in three main sections. If you got in each main 8.23 in3  each of the sections then your marks should be 24.69. this marks only counted-

as for your percentile because the gk marks is not counted in the total marks obtained in this exam but the gk marks is taken for allowing the student for other sections and create an opportunity for further shortlisted candidate for interview.

This marks to 24.69 your  percentile ofmarks maybe 74to72.

Hope this helps