Chapter 11 bankruptcy is often utilized by corporations because corporations are not entitled to exempt any property nor receive a discharge in Chapter 7. Corporations do not qualify for Chapter 13 and would not be entitled to exempt any property nor receive a discharge in Chapter 7.
Chapter 12 bankruptcy is used by certain farmers to avoid foreclosure of their real estate and repossession of their farm equipment, by creditors.
Only "family farmers", meeting certain requirements, qualify for Chapter 12.