Do you mean which server pod your instance is hosted? If that's what you mean, you can look at the URL of your Marketo instance to deduce the data center where your pod is hosted. It's not 100% clear, but here's what I know generally:
Example: app-abc.marketo.com/#SLXXXXA1
The "App-XXX" portion of the URL indicates which server pod you're on. You'll see some abbreviations there and according to other posts on the community, here are most of them:
The Nth host. Like if you have 20 hosts in a Data center (assuming no additional load balancing) they're 01-20. Standard public naming convention instead of calling them Abel, Brian, Chrystal, etc.