How to Buy In the Name of the Tsar Right Now
If you want to play In The Name of the Tsar right now there are a few ways to make that happen.
You can pickup the Premium Pass, the Battlefield 1 Revolution bundle, or you can simply buy the DLC as a standalone DLC.
The Battlefield 1 Premium Pass is a $50 season pass that nets you all four DLC expansion packs, access to the CTE, several superior Battlepacks, priority access in game queue's, and more. Battlefield 1 Revolution is the game plus the Premium Pass.