Sun in the 12th house is not welcome as it may lead to many health problems. 12th house is not a good house in general as it is connected to loss, health problems and problems of the bed. Serious health problems are indicated when the person is 36 years old. He may be accused of killing a cow. The pleasures of the bed may be elusive to such a person. Leprosy is indicated if the 6th house lord is conjunct the Sun in the 12th house. However under certain conditions there are no problems. Watch this video to know what are the conditions that causes the exceptions.
Click on the below link to watch the video and learn more about the Sun in the 12th house.