Fortigate 60D - WAN Link Traffic Division Requirement is to divide the WAN zone traffic Two different LAN IP group's internet traffic should go though 2 different WAN connections in fortigate 60D (Currently its WAN Zone(wan1 and wan2) . How to do that configuration?

Just providing 2 egress policies won't suffice.

Traffic to unknown target networks has to follow the default route. But, there is only 1 default route per system/FGT (for obvious reasons). To match a (static) route the FGT only looks at the destination IP address.

In your case, this is not enough because you want traffic from different sources to follow different routes through different interfaces. For this, use a Policy Route. To match a PR, you can specify the source subnet address as well as the destination (which is '0.0.0.0/0' for the default route).

So the steps to take are:
1- pull WAN2 from the WAN zone to make it addressable. WAN1 remains in the zone, no changes required.
2- create a Policy route as mentioned, through WAN2
3- create an additional egress policy for 'lan' to 'WAN2'. Don't forget to enable NAT!