Being free from the law of sin and death is a metaphor for not being controlled by the law of sin and death. Alternate translation: "has caused the law of sin and death to no longer control you" (See: [[rc://en/ta/man/translate/figs-metaphor]])
Possible meanings are that this refers to 1) the law, which provokes people to sin, and their sin causes them to die. Alternate translation: "the law which causes sin and death" or 2) the principle that people sin and die.