Hi,
Yes, it is possible. However, as vRO can use only a single vCente/PSC endpoint as authentication provider, in order to be able to use vRO context actions in your multiple vCenters, they must be configured in such a way that each of the vCenters can validate other vCenters' SAML tokens.
See the following recent thread in vCenter community forum where the same use case is discussed - https://communities.vmware.com/thread/604784