The Maximum array LUN size supported with the latest version of ONTAP is approx 3TB and it’s documented in V-Series support matrix available on now.netapp.com.
However, Based on your question, it sounds like you are describing mapping one array LUN to an Aggregate for one specific host or application. While this would work, I would recommend you take different approach. When creating your NetApp aggregate, you should use multiple array LUNs to create a larger aggregate. This way your storage pool (aggregate) can me very large containing multiple array LUNs and used for multiple hosts.
There is some good documentation in V-Series Best Practices (TR-3461) http://media.netapp.com/documents/tr-3461.pdf