This tells Google to look for pages that have the exact phrase index of in the page title. Web servers often generate such titles for directory listings (e.g., Index of /movies/ ). These pages show all files and folders inside a directory if directory browsing is enabled.
The search term intitle:index of "new bollywood movies" is a Google Dork used to find open directories on the internet that host movie files. These directories often appear as a simple list of files and folders (an "index") rather than a polished website. intitle index of new bollywood movies better