If suppose I want to add web part zone in master page can I add it? Need short explanation.

The straight forward answer is Yes, you can add it. Now it depend on the requirement how you add it. Just edit the MasterPage in SharePoint designer and add the WebPart zone from ribbon and save MasterPage. And now when you apply MasterPage to any page and edit the page, you will find option to add WebPart.

Yes we can add it...Just take the snippet for webpart zone and add it into the master page