they can be left until 8 weeks , from the moment they are out nest around 3 weeks they start to try foods the mum eats and watch her so they learn how to use water bottle etc, and being with there mum till 8 weeks means when they do leave to be rehomed or go to own hutch they cope with it a lot better, however they can be took out at 6 weeks but its not recommended, in cases where the mum rabbit is not freindly or is very nervous its often done , because her behavouior rubs off on to the babies they watch her and think this is normal, so they get took away at 6 weeks and you can keep them all babies together and handle them lots so they come round and get used to people, this way they have 2 weeks of human contact before you decide at weeks to keep or find a home
they should be weaned by 6 weeks and eating normal food but will still try and get mums milk, some people recommend not letting them eat greens or veg till 12 weeks, i on other hand let my babies try the mums veg and seed from point they leave nest 3-4 weeks as they get used to it and they only have little nibble (i dont fed them directly i give to the mum and sometimes they like to have a try of what she eats), this way if they get rehomed and they get fed greens they are used to it and less chance of stress or upset bellies or even the bloat