This sector of the old CIT was once one of the most advanced robotics research facilities in the United States, where the CIT pushed the envelope and limits of conventional robot research. As the Institute burrowed into the ground and built its own subterranean metropolis, the old sections were gradually abandoned, until they were finally filled with surplus combat robots and sealed off. The only part of the old Robotics lab that remains in use is the one that houses the molecular relay and elevator to the Concourse.
The area is accessed after during the quest The Nuclear Option's Brotherhood path or the Railroad path. The player character, assisted by Elder Arthur Maxson and a sizable Brotherhood strike force or Desdemona and Tinker Tom, has to cross the linear gauntlet of old protectrons, a sentry bot and old synths to reach the Concourse elevator and be able to strike at the Institute.
The Institute old Robotics appears only in Fallout 4.