Registrars accredited by HKIRC can help you register .hk and .香港 domains. Some of them may offer other service(s) as well like web-hosting, email service, website design etc. You may wish to select the registrar that best fits your needs.
2021 Best Registrar Performance Award:
Gold: Speedy Group Corp. Liimited
Silver: Udomain Web Hosting Company Limited
Bronze: CSC Corporate Domains, Inc.