Getting various error for multiple approaches. seems not able to import xrm.sdk in other than .Net Framework.
I'm trying to import Microsoft.xrm.sdk in .Net standards. but I couldn't find anything
compatible
(not compatible). I have tried the following reference
Microsoft.CrmSdk.XrmTooling.CoreAssembly
Microsoft.Xrm.Sdk (2015)
Microsoft.Xrm.Sdk (2011)
Package import Failed: NU1202: Package Microsoft.CrmSdk.CoreAssemblies 9.0.2.24 is not compatible
with netstandard2.0 (.NETStandard,Version=v2.0). Package Microsoft.CrmSdk.CoreAssemblies 9.0.2.24
supports: net462 (.NETFramework,Version=v4.6.2)
Package restore failed.

That is correct. The Dynamics 365 SDK requires the full .NET Framework.
On a related note, Microsoft has released an alpha version of the .NET Core-compatible SDK.