6th house belongs to Mercury and Ketu also has its effect on this house. So this house will give combined effects of Mercury, Jupiter and Ketu. If Jupiter is benefic the native will be of pious nature. He will get everything in life without asking. Donations and offerings in the name of elders will prove beneficial. If Jupiter is in 6th and Ketu is benefic then native will become selfish. However, if Ketu is malefic in 6th house and Mercury is also malefic the native will be unlucky upto 34 years of age. Here Jupiter causes asthma to the native's father.