There is an endpoint for downloading TensorRT packages for amd64 devices (https://developer.nvidia.com/nvidia-tensorrt-download) but this download does not include downloads / updates for TensorRT for TX2 devices. The only way to get TensorRT for the TX2 seems to be from downloading Jetpack. This makes it hard to update packages piecemeal, or download / update / reinstall packages in-place.
For example, it would be awesome if TensorRT for the TX2 were updated to CUDA 9.2 - maybe it already is, but I don’t know where to find the download.
Where can I find the download page for TensorRT for arm64 devices, namely the TX2?
As you have discovered, the packages for TensorRT / CUDA / cuDNN for Jetson (aarch64/arm64) are downloaded by JetPack and not hosted online. The versions of these packages are typically tied to specific releases of JetPack-L4T BSP, so it is easier to keep everything in sync that way.
The latest official supported release for TX2 is JetPack 3.3 with CUDA 9.0, cuDNN 7.0, and TensorRT 4.0, however unofficially some users have reported they are able to install JetPack 4.1 L4T BSP and packages intended for Xavier to TX2 (for your experimental purposes):
[url]https://devtalk.nvidia.com/default/topic/1042942/jetson-tx2/jetpack-4-1/post/5290610/#5290610[/url]