I'd look into AV1 decoding benchmarks, regardless of NVIDIA vs AMD, as I've been using NVIDIA on Jellyfin for a while with no issues.
HEVC is not as relevant IMO, as it's not available through browsers due to license restrictions (ffmpeg / mpv works fine), so I'd focus on AV1 capabilities, which is not available in many cards.
AV1 decode is supported on the RTX 3000 series, encode + decode in the RTX 4000 series
For Intel Arc, AV1 encode + decode support is present on all Arc Alchemist GPUs,
For AMD, AV1 decode is on RX 6000 series, encode + decode on all RX 7000 series GPUs
As someone else has recommended, a low end Intel Arc alchemist GPU is pretty great for stuff like Jellyfin, very low price to entry for gfx accelerated AV1 transcoding.
The nvidia 1650 can't do AV1 but it can handle hevc just fine, I'm currently using a 1660 on mine and before that it was a 950. Unless you need more than 3 steams at a time you should be able to get it working.