I need to create a report on Jaspersoft that displays randomly for example 6% of clients and from this 6 %, I need 25% female and 30%male.
As a starting point, refer to the Jaspersoft Studio Guide for assistance with using the development tool itself. There are also samples that you can load into Studio which is inside the JasperReportsSamples project that you can open. It contains many report samples that you can browse and run. However, for this specific requirement its best to plan it out on how you want the report to look but it looks like you want drill down from a parent report into a child report.