Hi @Srinu Raavi ,
Unfortunately, I don't think this is possible. AzureRm.Website returns a Site object, which doesn't contain any property related to an App Service runtime. AzureRm is being phased out, replaced with Az.
Get-AzWebApp returns a PSSite object which is like Site and it also doesn't have a property that identifies the runtime. The docs are complete for the PSSite but ran the command just to make sure.