The "x64" in the keyword signifies that this software is built exclusively for 64-bit operating systems. Here are the baseline requirements for Revit 2021:
The search term typically refers to a pirated or "cracked" version of the software hosted on FileCR. While FileCR is a known site for downloading various software, downloading professional tools like Revit from unofficial sources carries significant security and legal risks. Software Review: Revit 2021 Key Features autodesk revit 2021 x64 multilingual filecr exclusive