Remember the battle with the PUPA? And the one with Attack Chopper Mi-24A? Well this is basically a battle with both of them combined. Chrysalis has high maneuverability and high attack power. The reason why I chose the FIM-43 over the RPG is because the Chrysalis moves a lot and the FIM locks on the target -- unlike the RPG.
Now take a look and find all the pillars in the area. What you need to do is to take cover whenever Chrysalis uses the Chain Gun and once it stops shooting stand up, lock on to him and shoot. When you're out of FIM ammo, move around while avoiding the Chain Gun and when you hear it say Charging or Railgun, you'll see a red line pointing at you. Keep moving from left to right to avoid it.
When it starts its attack form take out your M60, aim carefully and shoot the complete clip on it. When the chasers appear, change to Auto Aim and shoot them down with the M60 (they only take 2 shots). Use your Support Supply Marker whenever you are out of ammo. Pretty simple fight. Use your Surround Indicator to keep track of where he is since the mist is too thick to see (like shown in the picture above).
Once the OPS is over you'll be able to develop *Carl Gustav M2 2 and *Support Strike Marker 3 .