Raytracing was one of the stars of GDC 2019 this year, with both Unreal and Unity announcing DXR support. Unreal Engine support was available almost immediately with the release of Unreal Engine 4.22. Unity users on the other hand have to wait quite a bit longer, with the first official release coming in Fall of 2019 or later. Fortunately for the impatient Unity have released a highly experimental Unity build with raytracing support.
You can download the experimental build from Github here with compiled zipped binaries available here. To fully make use of this version you need to have Windows 10 version 1809 or higher installed as well as an RTX card (even with the updated drivers from NVIDIA, this install will not work on 10 series cards, unlike Unreal Engine).
If you are interested in learning how Unity deals with real-time raytracing, you can download the PDF documentation right here.