Hello Levgen,
GOST beams are available out of the Box with Advance Steel, Depedning on installation they are sometimes referred to as GUS. The reason for this I am unsure.
There are two methods to add sections to Advance Steel. One method is to edit AstorOProfiles.mdb file located in C:\ProgramData\Autodesk\Advance\Data.
You will be able to copy an existing I Section, channel, hollow profile or angle table, then rename and edit according to the dimensions and properties you require. I do recommend making a backup of the default AstorProfiles.mdb
The other method for non standatd type sections such as extruded aluminium is to create a user profile. The link below goes through this process in great detail.
http://www.graitec.com/uk/FAQ_view.asp?FAQID=923&Language=EN&Name=How+is+a+user+section+created+for+...
