Depends haevily on the manufacturer.
But for me it was pretty much everything in mp4 (and newer probably also can do mkv) in H.264.
I'd avoid H.265, with the exception for very new and fancy tvs (usually OLEDs and higher end TVs from >2018.
Never do AV1.
Also keep in mind, that not every audio-codec has support.
Try to go stereo or (I think AC3).