It was a network configuration issue.
My VCenter has 2 NICs, 1x Server VLAN, 1x Management VLAN.
I configured VSC for Management VLAN - installation went through but somehow it did not properly connect. Changed it to Server VLAN and now everything shows up in vcenter.
Nevertheless I now have the problem, that I have added my FAS2650 by using the Cluster Management LIF IP.
Interfaces are shown but no SVMs or Datastores. I have added the Users/Roles with Netapp RBAC User Creator on the Cluster and Datastore SVM.
I have also tried to add the SVM itself, and not the cluster, that works but VSC says that some permissions are missing:
Missing all access commands:
job,volume efficiency off,volume efficiency on,volume efficiency show,volume efficiency start,volume efficiency stat,volume efficiency stop,vserver iscsi interface accesslist add
Missing read only access commands:
vserver fcp initiator show,vserver fcp interface show,vserver fcp show,vserver iscsi connection show,vserver iscsi interface show,vserver iscsi session show,vserver iscsi show
I have double checked the permissions, I tried to assign the role created by RBAC-Creator and also assigned vsadmin role to my VSC-User. Sometimes I see volume creation and destroy-permissions, but Discovery never shows up.
I had the same issue that SVMs were not discovered with Version 6.2 (Windows), but it was fixed with 6.2.1P1D2.