There isn't a maximum it just gets riskier the longer you wait because the tendons and ligaments that hold the pelvic bones get stiff and then the bones can't separate to let kits pass. Exactly how fast that happens or if it even reaches the point of being a danger depends on the rabbit. So maximum age for a first time litter is completely a matter of opinion on how much risk you think there is and how much risk you are willing to take. One of my first does gave birth to her first litter at over 2 years old. She did get a big kit stuck but that just happens sometimes. She got it out without help, had 2 live kits, and went on to have 3 or so more litters before I sold her to keep her daughter.
Minimum age also depends. Usually 5-6months for small breeds and 6-8months for large breeds, giant breeds even closer to the higher number, is considered the earliest to breed. Each rabbit matures at it's own rate though.
