Conversion of grades

I received my grades on different scales. 9th std in the form of letter grades a1 b1 etc and 10th and 11th on number scale. should I convert my grades on gap scale if I have an 85% right now because 85% on WES scale is 4/4

Unless the university specifically asks you to convert (and very few do), you don’t convert. If they want you to convert, they will tell you how.