Kundlis 6th, 8th and 12th houses not always bad.6th house in Astrology :In general way 6th house is not good, as it deals with Enemy, hospitals, Diseases,Litigation, Court cases, Debt etc. 6,8,12 a good combination for accidental injury and expenses in hospitals. As we know every house is important and we know that how 6th house is good for profession, 6th house also shows stability, being 12th of 7th house this is not good for married life and partnerships but good for profession. it depends whether 6th house is connected with benefice houses or not , 6th house connected with 11th house is good for competitive exams, win in court cases, success in Betting, getting bank loan and repayment of loans, win over enemies and in elections too. so these are the qualities of 6th house. So every house is good and bad, we must know what is good and bad for us.8th house in Astrology :As we know if we talk about the most malefic planet and house, generally considered it's 8th house and it's lord. Most of the people/Astrologer consider 8th house/lord most dangerous and spreading phobia all the time. 8th house deals with sudden loss, Accidents, Nature of Death, Longevity etc. The planets placed in 8th house is considered weak and unable to bestow good results and the planet under influence of 8th lord are also weak/bad.But they mostly see the one sided view of the coin, no planet is weak, weak for what? May be weak for relationship but good for career.. depends on their placements and aspects. Every house is important and have its own quality, a strong 8th house is good for longevity , it blesses with very active and sharp mind , research oriented (Scientist) , knowledge of occult science (Astrology, Tantra-mantra), Sudden gains, Gains through insurance , paternal property and foreign connection, Intuition Power, sex etc . Everything comes in combo(Positive ,negative), it depends on us how we accept this.For Example if 8th lord placed in 1st house with yogakarka Planet, The person may have deep interest/knowledge/gains in Astrology.12th house in Astrology:As most of us consider 12th house malefic as 6th and 8th houses, in a general view 12th represents expenses, losses, hospitals, Imprisonments etc. bad things. If we see the other part of the coin, we found that 12th house is also a very important house as it represents good things also. As if 12th lord is well placed, you get good gain and support from society , 12th house is called the door of Heaven , that means it makes a person spiritual too in the old age. We can see bed pleasure from 12th house. For foreign travel or long distance travel, 12th plays the major role. Depends on the past karma these malefic houses 6th, 8th and 12th and their lords creates Rajyoga and Viparit rajyoga is considered stronger than normal Rajyoga.