When Valorant was in its closed beta stage, the game did have a ranked system but that was removed when the game actually came out along with the COmpetitive mode.
While Riot did not announce when the ranked mode will be coming back, it should be added back into the game when the game gets some of its first few patches. They said that they dod not know when that will be but seeing as the developer has been pretty hard working and coming out with patches constantly, we might see this getting to the game soon.
The reason why it was removed in the first place was that they wanted to improve on the system but they also wanted to give all players the same starting time. With the ranked mode gone, those that did not play the beta will get to learn the basic first and catch up to those that did.
Modes that are currently available are Unrated mode and Spike Rush.