Hi @Kadir ,
the VM SKU for 64 vCPU and 512 GB RAM are for instance:
Standard_E64d_v5
Standard_E64ds_v5
Source: Edv5 and Edsv5-series
This VM series should be available if almost every Azure region/Azure datacenter.
In which Azure region/datacenter you want to deploy the VM?
(If the reply was helpful please don't forget to upvote and/or accept as answer, thank you)
Regards
Andreas Baumgarten