vRA usually means vRealize Automation, which is different
though restarting the vms without vcenter isn't that easy, and you can't really protect vcenter with vsphere replication.
I've also veeam for backup and then it protect VCSA.
In case of DR, if VCSA is not protect , It Is not problem.
My doubt, is if i can power-on the protect VMs in case of dr , if VCSA is down....and if i can protect VMs on esxi with local datastore.
First and foremost,DR cannot be performed within one single vCenter. vSphere Replication is registered to your vCenter due to which vCenter should ideally be accessible in order to acess vSphere replication user interface.You should ideally have two different vCenter if you call it disaster recovery.
Yes you can replicate within the same vCenter. Even in that scenario fail-over of servers is only possible if the current vCenter is up and running.There are other ways to power on the servers but that would involve command line.
Hope this helps.