To answer your question: His real name is Andy Biersack, also, there is only on "X" in Andy Six, he says so and it is পোষ্ট হয়েছে as so on his myspace.
Yeah. He changed his name to Andy Sixx because at school when he did sports his number on his শার্ট was always 6. He likes being called Andy Sixx অথবা A6.