I have tried looking into the creation of a PowerPoint presentation using C# but i was not able to find how i would clone slides from a template and add charts to a presentation slide on the fly using C#.
After the presentation has been created save the file as well.
Using Aspose.slide for .NET
You can also refer to the following useful links:
Cloning Slides including Images and Charts in PowerPoint presentations & Using Open XML SDK 2.0 Productivity Tool
Add Chart on the fly to PowerPoint
Create PowerPoint .PPT programmatically using C#
How to create a PowerPoint presentation using C# and embed a Picture to the slide