If you want to use javascript functions as formatter functions etc. in highcharts in Jasper Reports you need to set / add in main server property file “…your_path_to_jasper…/WEB-INF/classes/jasperreports.properties” this property:

com.jaspersoft.jasperreports.highcharts.function.properties.allowed=true

This property must be set globally on server – so far (version 5.6) you cannot use locally in report.