Some archives include a "recovery record." If your file is corrupted, you can try opening the archive in WinRAR and clicking the button. It may be able to rebuild the damaged data in part2 without requiring a fresh download.
When a file is too large for certain servers or storage devices, it is "split" into smaller chunks. In your case, part2.rar is just one segment of a larger whole. To access the contents inside, you need every single piece of the puzzle—usually labeled from part1 through however many segments were created. Common Issues and How to Solve Them sc23996-NFSRM11.part2.rar
: If sc23996-NFSRM11.part2.rar is significantly smaller than the other parts (and it isn't the very last part), it likely didn't download completely. Try redownloading that specific segment. Some archives include a "recovery record