By default, Tomb Raider: The Last Revelation’s frame rate cap is unlocked, so there is nothing you need to do to unlock it.
Tomb Raider The last Revelation (Steam) Save data Is Located in : Steam\steamapps\common\Tomb Raider IV The last revelation\savegame.X
X = Numbers
There are few settings can be tweaked at the launch settings (or first launch)
Some settings can be tweaked at the launch options
There's no many settings in Tomb Raider The Last Revelation.