If you registered your domain with us recently, then maybe the DNS are not propagated completely. The registered domain normally becomes available after 24-48 hours after the registration.
If you have registered the domain with other registrar, you will need to change the DNS with the one’s who provided your domain, and double check that it point to us. Once completed you also need to wait for it to get fully propagated.
DNS propagation usually takes 12-24 hours.