Open the Library tool settings box.
Set the top left box to "Find Library Parts" in stead of the default "Folder View".
Type in railings.
You can also make custom railings using the Curtain wall tool or Trussmaker addon.
HTH
Please add you OS and version of Archicad to your profile as these sometimes affect the answer.
Erika
Architect, Consultant
MacBook Pro Retina, 15-inch Yosemite 2.8 GHz Intel Core i7 16 GB 1600 MHz DDR3
Mac OSX 10.11.1
AC5-18
Onuma System
"Implementing Successful Building Information Modeling"