As of R3 2016 there are Nuget packages built for ASP.NET Core. Please check the requirements and required settings in HTML5 Report Viewer in ASP.NET Core
The attached example uses the Telerik Reporting Nuget packages of v10.2.16.1025 - R3 2016 SP1.
Telerik by Progress
Do you want to have your say when we set our development plans?
Do you want to know when a feature you care about is added or when a bug fixed?
Telerik Feedback Portal
and vote to affect the priority of the items