To type correctly in Arabic you need either a plugin like World Tools from In-Tools.com or an Arabic localized version of InDesign. If your CS6 is part of a CC subscription you can change your language preferences in the CC application, then download the Arabic/English version to add Right-to-Left controls, otherwise its the plugin.
There is also a trick you can use to create a frame with RTL formatting. Make a text frame, then right click and choose Fill with Placeholder Text while you hold down the Ctrl (Win) or Cmd (Mac) key and you should see a drop down to choose a language. This will add the correct formatting for Arabic to the frame, but you will not have any way to access the controls, so it is really only good for small amounts of text, like pasting from the clipboard or possibly Placing a story.
Thank you so much for your reply but where should I download the Arabic/English version to add Right-to-Left controls??
Are you working with a stand-alone version of CS6 or the Creative Cloud version. Makes a difference. If stand-alone, the you will need the World Tools addon.