You're looking for a way to download the Grand Theft Auto IV (GTA IV) game in ISO file format. Here are some general insights and recommendations:
Grand Theft Auto IV is an action-adventure game developed by Rockstar North and published by Rockstar Games. It was released in 2008 for PlayStation 3 and Xbox 360 consoles, and in 2009 for Microsoft Windows.
An ISO file is a type of disk image file that contains the contents of an optical disc, such as a CD, DVD, or Blu-ray disc. In the context of game distribution, ISO files are often used to distribute games that are no longer available for purchase or download from official channels.