Depending on where the file was sourced, it usually contains one of the following:

A "repack" or cracked version of a title like GTA V , GTA: San Andreas , or GTA IV .

(where titles are occasionally offered for free)

Pre-completed game progress files ("100% Save Games") meant to be placed in the user's local documents folder. Safety and Security Risks

Downloading .rar files from unofficial sources carries significant risks. You should be aware of:

Unofficial archives are a primary vector for Trojans, ransomware, and miners. A file named "Grand.Theft.Auto.rar" is often used as "clickbait" to trick users into executing malicious code.

A collection of community-created modifications (scripts, textures, or new vehicles) for an existing installation.

Many of these files are password-protected to bypass antivirus scanners. If the site asks you to complete a survey to get the password, it is almost certainly a scam.