How can I clear my doubts if I get doubt while seening video

Hi krishna,
You have an option to post your doubt right under the video.
Just scroll down, you should have an option to ask doubt there.
If you do not have access to study room, only then you will not be able to post doubts.
Also, make sure, you let us know about the time-stamp where you have the doubt so that faculty can help you out faster.