Browsers often fail when downloading large RAR files. To ensure "part09" doesn't time out, use a dedicated download manager:
The file is typically associated with multi-part firmware updates or software packages for specific hardware, such as smart TVs, automotive systems, or industrial controllers. Because it is part of a split archive, you must have all preceding and following parts (e.g., part01 through the final part) in the same folder to extract it successfully. Download S68AT06 LF1V018 part09 rar
You cannot open "part09" by itself. RAR archives split into parts act as a single unit. How to Safely Download & Install Files from the Internet Browsers often fail when downloading large RAR files