You cannot open "part05" by itself. You must have parts 01 through 05 (or however many exist in that set) for WinRAR or 7-Zip to merge them into the usable firmware.
If you have successfully gathered all parts and extracted the .bin or .img file, follow these steps to update your TV: Download MT5507 3840x2160 Videocon part05 rar
Because high-resolution 4K firmware files are large, they are often split into smaller "parts" (like part01, part02, etc.) to make downloading more stable. You will need (typically 5 to 10 files) in the same folder to successfully extract the final installation file. Where to Find the Download You cannot open "part05" by itself