Your entry vignette, biometric permit or email from the Home Office will indicate if you need to register for the police.
If it says “Register/Report to Police”, “Pol. Registration” or similar, you must register with the police.
The Overseas Visitors Office (OVRO) further explains which nationals need to register, how to register and what you need to bring: https://www.met.police.uk/advice/advice-and-information/ov/registering-overseas-visitor/
You will need to register within 7 days of arriving in the UK. Please understand during peak times, this 7 day requirement might not be met as the OVRO are very busy. They may give you appointments for later dates following your first visit to their office. As long as you have been engaged in this process (i.e. attempted to register within the time period), the 7 day requirement is deemed to be fulfilled.
Keeping your certificate up to date
Guidance on completing the Pro Forma Form