Converting an Android APK to a Samsung TPK is challenging because the two formats cater to entirely different platforms—Android and Tizen OS. Here's how you can approach it:

1. Use Tizen Studio: Download and install Tizen Studio, Samsung's official IDE for creating TPK files.
2. Adapt Your App: If you have the source code, rebuild your app to be compatible with Tizen APIs. Samsung smart TVs primarily support web apps, often developed using React.js (which you're already using). Tizen Studio provides templates and tools to streamline this process.
3. Rewriting for Tizen: React Native does not directly support Tizen, so you may need to rewrite your app using a compatible framework like React.js or plain JavaScript for a web-based Tizen app.

Direct APK-to-TPK conversion tools, like the POLARIS App Generator you mentioned, are either outdated or unreliable. The most efficient method is rebuilding the app for Tizen from scratch.

If you’re developing apps for IPTV platforms, consider exploring examples like MagisTV Premium, an Android app that offers advanced features for smart TVs and similar devices. Examining such apps could provide valuable insights into optimizing cross-platform compatibility.

Let me know if you'd like further details on using Tizen Studio or transitioning your app for Samsung devices!