Even though the file has an extention of BIN. it has nothing to do with Daemon tools or virtual ISOs. If you open the file with text editor you can see this: Вложение 63311

It is actually a list of MapOjbect links. It is used for one purpose only - populating the map editor with objects. If you have clean ToE installed and delete all its index.bins from data.pak and a2-data.pak game and editor will still run without a problem, RMG will still be able to generate a map but the editor tool panel will be empty: Вложение 63312.

Long story short - after some research - index.bin is actually a database built on Microsoft SQL Server 2000 Desktop Engine back when  the game was made - so may be it can be opened with some kind of DB tool but my knowledge here is limited.