@Shashi Sorry, I don’t know all details about the technical features that are currently supported.
It could make sense to ask this question in the announcement thread or maybe even in a new thread in the Cesium For Unity section of the forum. (Preferably with technical information about what “Vector Maps” refers to, unless people are likely to know that from the context).
EDIT: I think the question was already asked here: Ability to render CZML / KML Data in Unity?