For this mission you should look at the Op map located on the contract, and decide what units to send where. Whether you will be dividing your forces for a quick recon, or keep your forces together for a slower search. Companies can be divided if need be, with each company made up of two platoons, and each platoon made up of four squads. 

As I understand it we have...

Mannys Mechs
2 Troop Companies
5 mechs
1 frigate

NBCM
1 tank
1 medical team
1 frigate

LMG
1 Aerofighter

Colonial Militia
1 troop company

VS

insectoid hive of unknown strength