Port forward with Fortiwifi 60D

Hello 

I got the Fortiwifi 60D connected to Actiontec MI424-WR verizon router. my connection is Lan cable from the router going to wan of the firewall , verizon router router has 192.168.1 subnet and the firewall has 10.1.2 subnet.

i got all my devices working fine through the firewall Except a gaming console which most likely need port forwarding.

I created Virtual IP as follow :

192.168.1.6  (This is the IP of the firewall given by verizon cable set as external in VIP)

10.1.2.102  (console IP given by firewall)

my question is , do i need to create another IP with the actual external IP of Verizon cable , if so would it be mapped to 192.168 or 10.1.2 ?

also when i set the policy the incoming should be wan1 and destination should be lan ?

Thank you 

Joseph