To get the Azure images available from specific publishers like Microsoft at a specific location, we can use the Get-AzVMImageOffer command. For example, the below command will retrieve all the images available in the EastUs location and from the publisher MicrosoftWindowsServer.
PS C:\> Get-AzVMImageOffer -Location Eastus -PublisherName "MicrosoftWindowsServer"
From the RedHat,
PS C:\> Get-AzVMImageOffer -Location Eastus -PublisherName RedHat