I INSTALLED TRIAL VERSION OF MS OFFICE PROFESSIONAL 2013 WHICH WOULD EXPIRE ON JULY-10-2013. CAN I APPLY FOR EXTENSION PERIOD SO THAT USE IT MORE 3-MONTH BEFORE BUYING

This is the third time you've asked this question, all in forums that don't deal with the issue. In one case it was suggested that you ask in a Microsoft Answsers/Community forum, such as the following:

http://answers.microsoft.com/en-us/office/forum/office_install?tm=1373118567282

I moved one of your posts to the Office 2013 & Office 365 ProPlan - IT Pro General Discussions forum, as I saw several similar questions there. So far, there is no other reply in that thread, but I only moved it 13 hours ago (at this moment). You may need to wait until Monday before someone replies.