What game is that from, I don’t recognize it.
My preferred tactic (if I couldn’t hack it and add it to my robot army) would be to use vehicle mounted weapons, or run the damn thing over with a truck or something.
If you are forced to engage it on foot explosives or high caliber weapons work pretty well. A Barrett .50, LAW rocket, or EMP grenades would be my choice to engage one on foot, preferably in conjunction with the Cloaking CBM or a hologram cloak.
Just be careful, and take it down like you would an AT-ST from Star Wars, or ED-209 from RoboCop, and you should be fine.