The most important component of your rabbit’s diet is grass hay (such as Timothy or Brome), which keeps the intestinal tract healthy; feed it free-choice, daily.
In addition to hay, rabbits are also fed commercial rabbit pellets and fresh, darkgreen leafy vegetables. Until they are fully grown (around 6 months), rabbits can have all the pellets they want. After that, assuming the animal is also getting hay and vegetables, pellets should be limited to 1/8 to 1/4 cup per day per 5 lbs. body weight. Pellets should be fresh and plain, without seeds, nuts or colored tidbits.
Fresh water (bottle or bowl) should always be available.