Hi @roshan, glad to hear you are getting up and running with the 4C.
In addition to the getting started documentation which includes considerable explanations (with code) of the main features of using the eye tracker, we have a complete range of ready to run samples programs available @ https://github.com/Tobii/CoreSDK
with additional interaction API examples @ https://github.com/Tobii/interaction-samples
Furthermore, there are a few tutorials made a while ago related to the now deprecated Gaze SDK so the syntax will
be different from the Core SDK but perhaps still useful for you:
http://developer.tobii.com/category/tutorials/
If you manage to run through all these links and are comfortable in understanding their use, I should say you will be well on your way to developing an expertise in eye tracking programming!