Yes, you're welcome to register any domain names on DomainRegister, without buying/having any hosting plan with us.
You can, at your choice:
- use our DNS infracture to point your domain on any external hosting service
- or use your own DNS servers
- or keep your domain parked, waiting for an hosting service to do in any future
- or redirect your domain on another, yet existent website
- or just register your domain, and buy hosting service in the future, when you'll need it