I have an application written in Java FX. Will this run on Win8RT or Windows on tablet. If not, Is there any mechanism via which I can port to code to run on WIN 8 RT platform.
Your JavaFX application will run on a Windows tablet (e.g. Windows 8 tablet like a Surface Pro); it will not run on Windows RT. Supported JavaFX 2.x platforms are listed on Oracle's support site.
There are ongoing community efforts to port JavaFX to run on Android and iOS (based on OpenJDK, OpenJFX and RoboVM or Dalvik), but no current efforts to port JavaFX to run on Windows RT.