Industrial District GCR Comms tower is located in the northeastern part of the district. You need to approach it from the east side and grapple onto the rooftop of the building holding the tower.
There are seven goons you need to dispatch there. You will see a green shining panel. Brawn beats brain here so smash the panel to Enigma’s dismay. Next, drop down from the north side of the building onto another group of bad guys and after dispatching them, do the same with another power panel. This will disable the electricity protecting access to Enigma’s jamming gear, back on the roof you just jumped from. Go back, hack the equipment, enjoy bringing yourself even closer to 100% game completion.