Select the newly created security group, then click on the Inbound tab.
Add the same security group as the source for All Traffic. This allows all the traffic within the security group (all instances having this security group can communicate on all the ports)
Now the security group is all set and can be reused while creating a Vora Cluster. When launching SAP Vora Manager AMI use this security group.

As long as clusters are created in the same VPC, the same security group can be used. If you want to create another cluster or clusters in other another VPC, new security groups must be created.