Hi @supriya, in fact the XR SDK is part of the Tobii Tech Business department (us!) so we can help you regarding this query.
I understand you are trying to the find the eyeball co-ordinates in 3D space? I am afraid the individual eye ball co-ordinates are not exposed with the XR SDK but instead for a unified combined eye position for which we describe the methodology for obtaining this @ https://vr.tobii.com/sdk/develop/unity/documentation/api-reference/
Origin Vector3 The point in world space for the origin of the gaze ray.
You can also check out usage example @ https://vr.tobii.com/sdk/develop/unity/documentation/usage-examples/ which show the code in action.
Hopefully this answers your query, please let us know if we can provide any further information.