7th house Lord in 6th house
1) Before knowing effect of 7th house Lord in 6th house we have to know about Seventh house and Sixth house. As 7th house Lord is placed 12th from own house so you may read First house lord in 12th house.
2) According to a famous ancient classical book of astrology sage suggested that
दारेशे रिपुभावस्थे भार्या तस्य रूजान्विता।
स्त्रिया सहाअ्थ वा वैरं स्वयं क्रोधी सुखोज्जितः।।
General meaning of this shlok is when 7th Lord goes to 6th house then his wife will be Sicky. Native may be inimical to her and given to anger and devoid of happiness.
3)6th house is 12th from 7th house and when 7th Lord placed in 12th house it making relationship of 2-12th which is not consider good regarding natural significant of 7th house. It may cause a lots of bad results regarding 7th house.
4)7th house belong to wife and it is placed in 12th from own house so it may cause wife physical constitution may be weak. It may also cause native wife may be from out cast or from foreign country or follow foreign cultures which is not belong to native. Native wife may be suffering from disease or may be admitted to hospital. If 7th Lord is affiliated and weak in strength then it may be cause death of wife. Native may be faces separation or divorce from wife. If 7th lord have good Strength then it may cause two marriage and both wife will be survive.
5)7th house is kaam house and 6th house for disease or bad habits so 7th house Lord placed in 6th house may cause Sexual problems. It’s depending on natural significant of planet and condition of 7th house Lord. Native may have bad habits regarding Sexual activities. If Venus is also affiliated by impotent planet then it may cause weak Sexual power. Otherwise it cause Sexual disease and bad habits.
6)7th house is marak house for native and 6th house is a dussthan which carry disease so 7th house Lord in 6th house may improve marak capacity of Marakesh (7th house Lord). So native may be suffering from disease. If 7th house Lord is not well placed then it may cause critical disease. If worst placed 7th house then it may cause death of native. It may also cause of accidents or loss of body parts. Native may be suffering from fever due to excess body heat.
7)6th house also belong to enemy or legal problems and 7th house is belong to life partner or business partner so 7th house Lord in 6th house may cause legal problems with wife or business partner. There may be misunderstanding between Native and wife. Native and wife may be feeling enmity for each other. Native may be suffering from false blaming regarding marriage relationship. Native wife may be jealous by nature. So this may destroying marriage happiness between both couples.
8) 6th house belong to debits and 7th house belong to profession ( as 10th from 10th house) so 7th Lord in 6th may cause native may be suffering from debits regarding profession.
9) When 7th house Lord with 6th house in 6th house then it is not consider good as combination of o Lord of dussthan with Marakesh because Marakesh gets strength regarding his marak power in horoscope. It may cause marak for wife, native, and mama of native depending on horoscope and Dasha. Native may facing legal or debits problems from wife or business profession. Native may be cheated by others or may be suffering from thief.
10) If you want to know about effect of planet in 6th house you may read Planet in 6th house.