I just purchased the nexus 7 running android OS and I'm also new to arduino. Which Arduino software is compatible with my android tablet? Can I use the Mac OS X?
Which Arduino software is compatible with my android tablet?
That depends on what you mean by "compatible". What, exactly, is it that you want the Arduino to do? What, exactly, is it that you want the nexus 7 to do?
Can I use the Mac OS X?
On a Mac, yes.