Using GitHub Importer
To import repositories that are publicly accessible, you can use GitHub Importer.
About GitHub Importer
If your source code is stored on a code hosting service using Git, Subversion, Mercurial, or Team Foundation Version Control (TFVC) and is accessible from the public internet, you can move the code to GitHub using GitHub Importer.
Importing a repository with GitHub Importer
If you have a project hosted on another version control system, you can automatically import it to GitHub using the GitHub Importer tool.
Updating commit author attribution with GitHub Importer
During an import, you can match commits in your repository with the GitHub account of the commit author.