You can first file an application to the Norwegian Industrial Property Office for design registration in Norway. Then, within six months, you can file an application claiming priority from Norway. Priority means that your design takes precedence over later applications for the same design.
In this way, you have your application processed in Norway and you can receive assistance in correcting any errors and deficiencies before filing applications for other countries. This gives you more time to decide in which other countries you wish to register the design. The drawback is that it may become a little more expensive, because you will have to pay national fees to the Norwegian Industrial Property Office in addition to international fees.
Even if your application has not been fully processed at the Norwegian Industrial Property Office, you must file your application in other countries within six months if you wish to have priority from Norway. It is important that you heed the time limit of six months yourself.