Samsung sold a lot of Galaxy Tab S6 Lite tablets but they stopped sending latest updates long time ago. If you want latest Android 15 on it, there is a way and everything works as expected. This is for both WiFi only and LTE variants, but the LTE would not work. Other than that, everything works as expected.

Also, the US variants, SM-P610/P615N are not supported as well since bootloader cannot be unlocked. You would need One UI 5.1 Bootloader – February 2023 or newer, and a windows computer for flashing recovery and ROm.
Features of this Android 15 ROM for Galaxy Tab S6 Lite
Magisk support (v30.2 version pre-installed)
NikGapps support (Full version pre-installed)
Language support in Recovery Mode
Make sure not to provide any google apps or any files that provide root access as doing so will overwrite the patched system files and ROM may not work as expected.
Flashing instructions:
- Download ROM from here
- Reboot to recovery
- Sideload ROM zip
adb sideload PixelOS_15.0*.zip
- Format data
- Reboot and voila