No, the latest version is Lightroom 6.4 or Lightroom CC 2015.4
However, 5.7.1 may be the latest version that runs on your operating system, depending on what your operating system is.
Lightroom 5.7.1 is the latest version for Lightroom 5 edition.
But the latest release is Lightroom 6 and version 6.4.So,you have bought an older version.
Here the difference between these two versions Compare Lightroom CC vs. versions 5 & 6 | Adobe Photoshop Lightroom CC history