Public IPs - List all in Organization

We have AWS config service which helps to get a centralized view of all your resources in different AWS accounts within and organisation.

You can gather EIP (elastic IPs) insformation allocated in your accounts using AWS config. The config would also provide information on 'network interfaces' and IPs attached to it. Similarly, you can get EC2 instance along with IP information.

https://docs.aws.amazon.com/config/latest/developerguide/aggregate-data.html
https://aws.amazon.com/blogs/mt/managing-aws-organizations-accounts-using-aws-config-and-aws-cloudformation-stacksets/

Great thanks, I will check it out