Since you want to SSH into the zone from outside, it needs to have it's own IP address on the same network as the global zone. So either find a free address in the same network, or ask your network administrator to allocate one - whichever you usually do.
For the 'physical' setting; here (I think) is the simplest case: If you've allocated a single virtual network interface to your VM, then use that interface for the 'physical' setting
So, in the global zone, do
/usr/sbin/ifconfig -a
to list your interfaces. It should say something like
lo0:1: flags=2001000849<UP,LOOPBACK,RUNNING,MULTICAST,IPv4,VIRTUAL> mtu 8232 index 1
inet 127.0.0.1 netmask ff000000
bge0:1: flags=1000843<UP,BROADCAST,RUNNING,MULTICAST,IPv4> mtu 1500 index 2
inet 123.45.123.45 netmask ffffff00 broadcast 123.45.123.255
Here the interface name is bge0. (lo0 is the loopback interface; you don't want that) Yours will likely be called something different - maybe e1000g0, depending on what kind of a network interface VMWare presents.
Note that since you're using the same network interface in the global zone and the child zone, you must choose an IP address for the child on the same subnet as the global zone's.
In the example above the netmask for bge0 is 255.255.255.0, which means your child zone IP needs to be between 123.45.123.0 and 123.45.123.254