Everywhere in Australia. The NDIS is a national scheme, available in every state and territory, cities, regions and remote areas alike.
Wherever you live, the access requirements and the scheme rules are the same. What varies by location is practical: provider availability differs between metro and remote areas and in some remote regions the NDIA works differently to connect people with supports.
If your choice of providers is thin in your area, plan management helps. It opens up the option to work with non-registered providers, which widens the pool considerably. Email hello@providerchoice.com.au if you'd like to learn more.