Providing the where you saw this file name would help narrow down exactly what it contains.
2-20474-1-2-1539703265.7z 1250.53 - Extracting Immersive Dawnguard Dayspring Pass (IDDP)-4126-1-0-3.7z 1250.79 - Extracting IDDP - Official Long Tan After Action Reports 1-6.rar
In the gaming community, especially for titles like Skyrim or Fallout , files with simple numeric names like "1-6.rar" are frequently used for or versioned updates. Providing the where you saw this file name
Reports on enemy contact near Long Tan, air strike assessments, and soldier accounts from Operation Smithfield. air strike assessments
It may represent "Volumes 1 through 6" of a larger dataset that was split to bypass email or server upload limits.