3rd house is affected by Mercury and Mars, both enemies of Ketu. Number 3 would have an important role in the life of the native. If Ketu in 3rd house is benefic then his children would be good. The native would be God fearing and a gentleman. If Ketu is in 3rd house and Mars is in 12th then the native has a son before 24th year of age. The son would be good for wealth and longevity of the native. The native with Ketu in 3rd house usually gets a job, which entails long travels. If Ketu in 3rd house is malefic then native loses money in litigation. He gets separated from his wife/sisters-in-law. If such a native lives in a house with its main gate facing south, he will have serious problems regarding children. Such a native cannot say no to any thing and so will always have worries. He will have troubles from his brothers and will have to travel uselessly.