Conversion from IGES to Revit is not supported yet :(

IGES (Initial Graphics Exchange Specification) was among first vendor-neutral CAD formats designed to enable interoperability between different CAD systems. The latest versions of IGES have been approved by ANSI (American National Standards Institute) and published by US PRO (U.S. Product Data Association). The latest officially approved version of the IGES standard is version 5.3 which was published in 1996. Nonetheless, IGES remains a broadly used format (along with STEP) supported by all major CAD/CAM/CAE systems such as CATIA, Autodesk Inventor, Solidworks, Solid Edge, NX, Pro/Engineer, Creo and multiple others. IGES files usually have *.igs or *.iges file name extensions.

A .rvt file a three-dimensional model created by Autodesk’s Revit. Revit is a building information modeling (BIM) program that is used to create 3D building designs for floor plans, elevations and sections. It offers complete project lifecyle from conceptual design till fabrication and construction.