As of NSX version 6.3, the maximum NAT rules per ESG form factor are as follows:
Form factor | Number of NAT rules |
Compact | 2,048 |
Large | 4,096 |
Quad Large | 4,096 |
X-Large | 8,192 |
Please refer to Recommended Configuration Maximums for NSX at https://docs.vmware.com/en/VMware-NSX-for-vSphere/6.3/NSX%20for %20vSphere%20Recommended%20Configuration%20Maximums_63.pdf for the latest information.