Ketu, according to the author of Lal Kitab, represents son, grandson, ear, spine etc. 6th house is considered to be its 'Pucca Ghar.' It gives its exalted effect when in 5th, 9th or 12th house and its debilitated effect in 6th and 8th house. Dawn is its time and it represents Sunday.
Ketu represents the opposite node of Ketu, in the tail of the serpent. Its colours are black and white. Venus and Rahu are its friends, whereas Moon and Mars are its enemies . Forty two years is the age of Ketu. Ketu is also considered to be the bed. So the bed given by in-laws after marriage is considered to be auspicious for the birth of a son and as long as that bed is in the house, the effect of Ketu can never be inauspicious.