Hi, hit component will be the instanced static mesh component that has been hit (if it has hit an ISM) and hit index will be the index of the ISM inside that instanced static mesh component.
So you would cast the hit component to instanced static mesh component (if that fails then you haven’t hit an ISM with that linetrace) and then do remove instance with the hit index.
i.e. rather than “oceanplain” it
returns “BP_MapTerrain_2.OceanPlain
Plain”
I don’t know the naming conventions UE uses in game, but AFAIK the name is a unique identification for the object, so they can’t all have the name “oceanplain”