No, Tokyo is not Denever’s mother, since in the fifth season’s last episode, Deliver informs Tokyo that in the previous robbery, he lost his father, and he does not want to lose his sister in this heist.
Denver was raised by his father, Moscow, who abandoned Denver’s mother at a roundabout because she was addicted to drugs. For many years, Moscow convinced Denver that his mother had abandoned him.
Denver, along with his father, Agustn Ramos, was one of the criminals involved in the Royal Mint of Spain theft (Moscow). Denver was encouraged to join the robbery by his father, owing to some trouble he was experiencing with traffickers.
During the robbery, Moscow confesses the truth about Denver’s mother, causing a split in their friendship. However, he is quickly pardoned when Moscow dies after being shot by the cops.