CSHARP

get link element revit api

  UIApplication uiapp = commandData.Application;
            UIDocument uidoc = uiapp.ActiveUIDocument;
            Application app = uiapp.Application;
            Document doc = uidoc.Document;
			ObjectType obt=ObjectType.LinkedElement;
			Reference refElemLinked;
			Element linkedelement = null;
			
			refElemLinked = uidoc.Selection.PickObject(obt, "Please pick an element in the linked model");
                        RevitLinkInstance elem = doc.GetElement(refElemLinked.ElementId) as RevitLinkInstance;
                        Document docLinked = elem.GetLinkDocument();
						
						linkedelement = docLinked.GetElement(refElemLinked.LinkedElementId);

get linkinstance revit api

import clr
import sys
import System

clr.AddReference('RevitAPI')
import Autodesk
from Autodesk.Revit.DB import *
import Autodesk.Revit.DB as DB

clr.AddReference('RevitServices')
import RevitServices
from RevitServices.Persistence import DocumentManager
from RevitServices.Transactions import TransactionManager
doc = DocumentManager.Instance.CurrentDBDocument

elements = UnwrapElement(IN[0]) if isinstance(IN[0],list) else [UnwrapElement(IN[0])]

dicDocLink = {link.GetLinkDocument().GetHashCode() : link for link in  FilteredElementCollector(doc).OfClass(RevitLinkInstance) }

OUT = [dicDocLink.get(elem.Document.GetHashCode()) for elem in elements]