You can view the security groups on the ECS console at any time.
To view the security groups list, perform the following:
Log on to the ECS console.
In the left-side navigation pane, click Security Groups.
Select a region. A list of all the security groups in the specified region will be displayed.
(Optional) You can select VPC ID in the filter input box, and enter a specific VPC ID to search, then all the security groups under this VPC appear.