As well as being able to provide feedback on the draft R3 GCP directly to the ICH, stakeholders can also feedback to the MHRA:

https://www.gov.uk/government/consultations/consultation-on-the-international-council-for-harmonisation-ich-e6-r3-good-clinical-practice-gcp-guidelines

The MHRA have also published a blog summarising some of the key changes:

https://mhrainspectorate.blog.gov.uk/2023/05/26/ich-e6-r3-good-clinical-practice/