Hi Yar, Sheher
Azure OpenAI deployment maintains underlying data in respective regions for Data zone standard or Batch.
You can also restrain the data to your storage accounts in Australia regions
Reference - https://learn.microsoft.com/en-us/azure/ai-foundry/openai/how-to/deployment-types#data-zone-standard
We have support for Australia East which is IRAP-credited but not available in Australia Central
You can go through model summary table in below document to find supported regions for each Azure OpenAI model
(Region support for Azure OpenAI deployment)
https://learn.microsoft.com/en-us/azure/ai-foundry/agents/concepts/model-region-support (Region support for Azure AI foundry)
Hope it helps.
Thank you