Khogen,
Welcome to the forum. 
You can help us helping you when you post code, console output or error messages to format it as code here in the forum.
I don’t have access to an Azure tennant to test but my first step yould be to “drill in” the property you’re after and see how it looks. 
When a cmdlets outputs a list of properties instead of just one single properties you can use -ExpandProperty to enumerate this list … like this:
Get-AzureADDevice -ObjectId 86d62fa8-5366-49b7-85f8-439fd7c829eb |
Select-Object -ExpandProperty DevicePhysicalIds