You generally only need to right-click Part 1 and select "Extract Here" using a program like WinRAR or 7-Zip .
To make large games easier to upload and download, they are often split into smaller "parts." You have the 10th segment of that set. City.Bus.Manager.v1.0.7.0.part10.rar
v1.0.7.0 indicates this is a specific update of the game. For the game to work, every single part (part1, part2, etc.) must be the exact same version. How to "Put it Together" You generally only need to right-click Part 1