extension visitor visa

I have a VISITOR (Class FA) VISITOR (Subclass 600) Stay For/Until 3 Month(s) with multiple entries valid till 20 May 2018 (12 months visa grant) with conditions 8101 - NO WORK & 8201 - MAX 3 MONTHS STUDY I am in Australia from around last 2 and a half months, and my 3 months stay is...

Hello everyone!!!!! I am thinking about applying for an extension on my visitor visa for 6 more months. My original one was granted for 6 months since every entrance to Australia (multiple entrances until June 30th, 2015). And also I don't have the "Non further stay" restriction. So I just...