Answer:
you must wait until they are weened at about 8 weeks
Baby rabbits (kits), start to eat solids as early as 5 weeks old, and SHOULD NEVER be sold until earliest 8 weeks old. They still need the milk up until they are at least 6 weeks old.
DO NOT SELL UNTIL THEY ARE 8-10 WEEKS OLD AND ONLY THEN IF THE RABBITS ARE SHOWING SIGNS THEY ARE READY, kits can mate as early as 7 weeks old but if you want healthy rabbit babies, wait until it is 6 months old. You need to check sex also to separate them.
When they are 8-9 weeks old