The below can be found in quite a few documents regarding IPSec tunnels on NSX EDGE. Please elaborate:
"Upto 64 tunnels can be configured across a maximum of 10 sites"
Correction, size of the edge is deciding factor for maximum tunnel supported.
A great site to get all questions like this answered is: configmax.vmware.com.
Just have a look at:
Numbers depend on the product version.