There is only one file type that uses the .TR extension:
TomeRaider 2 eBook File
eBook created in the TomeRaider 2 (TR2) format, a software eReader available for PC, Pocket PC, and other mobile devices; supports fast searching and high compression levels; replaced by the .TR3 (TomeRaider 3) format.
|TomeRaider 3||Free Trial|
Updated: September 2, 2012