Slaughtering at home for your own family is fine, but under veterinary law meat for sale must come from a specialized slaughter facility, with veterinary inspection before and after slaughter and veterinary-sanitary documents. At a market, meat can only be sold from an equipped meat stall after a check by the market’s veterinary laboratory. Selling live rabbits is much simpler, which is why small farms usually sell live. Rules change, so ask the district veterinary station about the nearest approved slaughter point and the documents you need.
These answers are general information and do not replace a veterinarian. If your rabbit is sick, contact a vet.