So if it's a $5 fantasy coin can it be used in Australia or any where for $5 ?
No. This coin was never legal tender anywhere in Australia for $5. It was never "legal tender" anywhere
for $5 - not even in the self-proclaimed "Hutt River Province".
Hutt River Province's self-proclaimed leader at the time was Leonard Casley, calling himself Prince Leonard. In an effort to increase international recognition of his "country", Prince Leonard in the late 1980s authorized a friend of his, Kevin Gale from the Gold Coast, Queensland, to act as his ambassador and agent in selling Hutt River coins and postage stamps in America.
"Prince Kevin", however, went beyond his authority, and struck a deal with the Continental Coin Company in California to manufacture millions of "coins", without Prince Leonard's knowledge or consent. These coins were mass-marketed through American mass-media of the day (women's magazines, newspapers and such) and none of the profits from their sale ever made their way back to Prince Leonard. The "New Queensland Mint" is a fictitious entity, a trade-name which Continental used in an effort to make their coins sound more legitimate.
The issue of bogus HRP coinage did not stop until Continental Coin Company were eventually sued for mail fraud, over these and other "coins", on account that they were advertised as "legal tender coins" when they were not. CCC was shut down shortly afterwards.
Today, the coins are recognized as a legitimate part of the history of Hutt River (and I'm told you can find examples on display in the Royal Coin Collection) - but they are still not "legal tender" in Hutt River. If you turned up at the remote property in rural Western Australia where the Province claims its territory, they might good-naturedly accept one as payment (rather than bore a visitor with the long and painful story of why they're not legal tender, outlined above) but they are not legally bound to do so.
I own four examples of these "rebel" coins. So, in terms of classification, I personally file them in my world coin albums, wedged in between Hungary and Hyderabad, for "Hutt River Province - Rebel Issues". I also own a (much scarcer) "Hutt River Province - Legitimate Government" coin.
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis