I'm in need of help fixing the eye

[Riceball]

Hello, I'm trying to find a way to fix her eyes, but I have no idea where to even start. I have basic 3d modelling skills and i imported the head and the eye mesh in blender. The eye and the head matches, but in-game it doesn't. I'm assuming it's something else I need to look at. The eye is from a mod here called 2B race. I know from the start that the eyes wont fit the default fallout face and that's why I'm trying to figure out how to fit the eye. If only someone can guide me to the right direction to look at.