In this feature, an INAT(Inbound Network Address Translation) rule is added to the NetScaler appliance. When a packet generated by a client matches the conditions specified in the INAT rule, the appliance translates the packet's public destination IP address to a private destination IP address and forwards the packet to the server at that address.
This is typically used to map an external IP to an internal IP (without a proxy). This is a 1:1 true NAT setup (port usage remains unchanged). If you need to nat for 6 IP's then repeat x6. The IP presented to the server can ether be the client's, or can be itself Natted (actually PAT) to a netscaler IP.
https://docs.citrix.com/en-us/netscaler/11/reference/netscaler-command-reference/network/inat.html
http://discussions.citrix.com/topic/369303-inat-and-rnat-capabilities/