well i think there no point to be rude since he is your client and u have to provide the best of ur service
Just make him understand politely
The site is still under construction and it needs to be first developed and then submitted to search engines. We need to tell search engines about the site existence. It'd take some time. It may need bit of optimization as well. Very soon, you'll be able to find your site in search engines. Your patience would be much appreciated.