As we know Sixth house is First of Dusthasthana Houses (houses ==> 6, 8 and 12) and Second of Upachaya Houses (houses ==> 3, 6, 10 and 11). It represents things like diseases, debts, obstacles, enemies, disputes, daily routine life, colleagues at work place etc. One thing to remember here is that it is one of Upachaya Houses which improve with time. It means any planet in these houses improves in results with age and real good result is seen from a person’s 30s or 36s. Also, all the malefic planets provide very good results in Upachaya Houses but results may be seen in 30s or 36s.
Also, as we know about Seventh house, it is house of marriage, spouse, marital happiness, market place, other people (masses), business partnerships, agreements, etc.