I am curious, do you really have a Nano, or is it an Orin Nano? The two are very very different. The older and less expensive Nano is a TX1 in DIMM format. The Orin version can run from a JetPack 6.x install (which installs L4T R36.x), but the older Nano can only be installed by JetPack 4.x (L4T R32.x).
This also changes which JetPack can be used. The Orin Nano (but not the Nano) can use JetPack 5 or 6 on an Ubuntu 20.04 or 22.04 host PC. L4T is what actually gets flashed (which in turn is just Ubuntu plus NVIDIA drivers), and is tied to the JetPack release, so you could select either L4T R35.x (JetPack 5.x) or L4T 36.x (JetPack 6.x). See this release version chart: https://developer.nvidia.com/linux-tegra
Do switch to the Orin Nano forum since the releases and availability of software is far different than that of the older Nano.