I have never used oracle reports and I need to convert the .rdf from oracle reports to .jrxml in jasper so is there any way possible.
The Oracle reports Builder tool comes with a converter application (rwconvert.exe) that can take the report.RDF file and convert it into one of several report formats including an XML format. It may be possible to take the Oracle Reports XML report definition and transform it into a Jasper Reports XML file (.jrxml) either by hand or with the help of an xslt transformation script.
Take a look at this related question.
Additionally a quick google search also turns up some third party tools which will do the job to a greater or lesser extent.