Mo' Renown, no problems.
In Rainbow Six Siege, Renown makes the world go round. Renown is an in-game currency awarded through play and a few other methods. You can buy pretty much everything with the currency, except some premium items locked behind the paid-for Rainbow Credits.
Changes to the game since launch have changed the gaming, so Renown is no longer needed to buy the base operators or slap attachments on weapons. However, you'll still need it for the DLC operators and the game's extensive collection of cosmetics if you don't want to get out your real-life wallet.
Full story from the WindowsCentral blog...