According to latest reports Microsoft will be shipping a version of the new Office 2013 with Windows RT and that it will be the only non-Metro application that can be accessed on this particular version of the operating system.
It has been reported that Office 2013 RT, which is to be included on Windows RT will be a watered-down version of the full blown Office 2013. In this you will experience on standard Windows 8 or 7. Preview version of the Office 2013 RT will come pre-installed in Windows RT devices and you will be able to upgrade to the final version, which will come out next year.
Macros, third part add-ons, Visual Basic for Applications (VBA) support and some other minor things will be included in this list. Microsoft has stated that these features have been added to ensure better battery life and reliability on tablets. They also added that new Windows 8 and Office will offer a “No Compromise!” experience, but it seems some compromises had to be made.

Source : Blog.gsmarena