Look at the folder or website where it was downloaded; the parent directory often names the software.
Archival files like these are frequently used to distribute libraries or component packages for software like MATLAB, specialized PLC (Programmable Logic Controller) software, or civil engineering tools. CEMMGH_BM.rar
Use a tool like 7-Zip to open the archive without extracting it. Look for a readme.txt or version.info file inside to identify the specific feature it enables. Look at the folder or website where it