If i am having a url like localhost:4502/content/samplesite/Home-page/common-page1.html where common-page1 is child component, samplesite is parent component. How can i create template for the parent component?
First thing, those are not components at all. common-page1 is only page and samplesite is the website.
Also, if you want to learn Sling Resource Resolution, see this http://www.aemcq5tutorials.com/tutorials/sling-resource-resolution-aem/
Also - for AEM 6.4 - you should be building pages based on editable templates. See this article for more information:
As Ratna states - common-page1 is a page, not a component. Go through that article and you will learn about editable templates, pages, and components that populate pages.