set the current session language and set the rendering language of the report in Controller .
Check if this works
controllerobj.parmReportContract().parmRdlCOntract().parmLanguageID(‘Language ID you want ‘)
before calling the report ‘s start operation method.
this is actually passed to your report from the client during the execution.
You need to create labels used in the report in all languages and also have to add this to static designs present in report deployment settings and enable it and deploy it.
By default ax has some 12 or 13 reports that have multiple languages enabled.