I found out a way to import any roblox avatar into vrchat but it’s not fully done so if your character is buggy or something else use Blender 2.79 bc it worked really fine in blender 2.79 but not 2.8x or 2.9x. Anyways here’s the link will make update videos on this so stay tuned.
YT vid: How to upload any roblox avatar into vrchat [READ DESC] - YouTube
Blender 2.79 (recommended): Index of /release/Blender2.79/
VRC SDK3.0: VRChat - Home
Unity download: What's new in Unity 2018.4.20 - Unity
Hopefully this was helpful and if you got any question don’t be scared to comment! Np!