Record Minimum/Maximum Joint Angles
You can interactively set the rotational Min and Max values by rotating the item to the desired minimum direction and choosing Setup > Motions > Limits > Record Minimum Joint Angles (default keyboard shortcut: (). This will activate minimum limits for any rotational parameters (heading, pitch, or bank) that are currently active for the chosen item. Similarly, rotating the item to the desired maximum range limit and choosing Setup > Motions > Limits > Record Maximum Joint Angles (default keyboard shortcut: )) will automatically input the values into the maximum limits for the active rotational parameters.
You should deactivate Heading, Pitch, and/or Bank to avoid setting limits for channels you don't wish to.