server DNS address could not be found

I had add one eCommerce website in to server and changed the name server and published, but still now am not able to access the website, can you advise any way to resolve the issue.

This is the response while trying to access.

This site can’t be reached

alsultanmarket.com.kw’s server DNS address could not be found. Search Google for al sultan market kw ERR_NAME_NOT_RESOLVED