Requirements: I have to display same CMS page for different site so I have to create copies of 1 cms pages to display for other store-views. Is there any method to copy 1 cms page like we can do copy product to create duplicate products?
As far as I know you can't use one CMS page for different store views in Magento. Instead you should have different CMS pages for each store view.
And unfortunately it's not possible to duplicate CMS pages in Magento. But there are bunch of extensions which can do the job for you. Below are some of those extensions.
Hope this helps.