It can't be made available yet as the developers are still privately mining there 100,000 coins before they make the blockchain public.
This is on their website https://btcgpu.org/bitcoin-gold-community-response/
The fork has already privately occurred at a point known only to the Bitcoin Gold development team. The Bitcoin Gold blockchain will be made publicly available when the Bitcoin blockchain reaches block number 491,407, which is currently estimated to occur on October 25, 2017.
This bit they refuted but did not say exactly when it will be available. I have heard a lot of speculation about November 1st.
So it could happen quite soon but at the moment nobody can make a BTG transaction.