@Yukilizarz If the hair has bones already set up in blender, load up the model in unity then you put into the armature head bone It has to be under in the armature not the skin (or a seperate hair root) the VRC physbones script component
Be sure if you put it on the head bone to put all the bones that are not part of the hair (Like the tounge and eyes) into "Ignore transforms"
If you need a video tutorial i recommend Sipps physbone tutorial its very well made.