Ask you partner or NetApp contact to look for the following two limits in their tools/Docs
Core - Maximum number of connections - NAS
CIFS - Maximum number of connected share
I took notes of these for my platform when A NetApp engineer helped me to size my system (it was FAS3250 HA with ONTAP 9.0, the first figure was 100K Per HA (no cluster limit), and the second was 500K per HA (no cluster limit).
So this fairly old small spec controller (20GB RAM) and old OS version could do more than what sounds like you need.