Hi @amitsharmalko93, could you kindly clarify which hardware you are working with please as this will affect the ease with which you can access calibration data. With the Tobii tech range of eye trackers (EyeX, 4C) calibrations are handled automatically by our own internal API with associated data not being exposed in the Tobii Tech SDK’s (Tobii Core SDK Interaction API) @ https://developer.tobii.com/tobii-core-sdk/
With the Tobii Core SDK Stream Engine there is scope for custom calibration, however this requires the purchase of a special licence to do this and access the data.
If however, you have a Tobii Pro eye tracker, then calibration feedback data can be easily accessed via the Tobii Pro SDK so it very much depends on your licencing and hardware setup @ https://www.tobiipro.com/product-listing/tobii-pro-sdk/
If you could kindly provide us with some more information with respect to your specific needs and equipment, I will try to find the best solution for you.