I'm trying to use AWS lake formation to perform grants and revokes of permissions for AWS IAM groups, via console I can normally, but via Boto3 or AWS CLI I get an error stating that IAM groups are not accepted in these actions.
You can't. Groups aren't principals and can't be granted permissions using resource-based permission policies. If your Group and your LakeFormation stuff are in the same account, you should attach your LakeFormation permissions to the Group rather than using a resource-based permission policy. If they are in different accounts, allow the Group members to assume a Role from the LakeFormation account and give permissions to that.