9th lord placed in 4th house is it gives Raja yoga?

Is it true that saturn in 3rd house for simha lagna gives raja yoga in its dasha?

Some astrologer says when saturn becomes yogakaraka and placed in 6th or 8th or 12th house gives very good results. For example, for taurus langa, even debilitated saturn in 12th house gives excellent results. For libra lagna saturn in 8th or 12th house gives very good results. please comment.

Lagna adhipati, Dasamadipathi if placed in third house can it give any raja yoga

For Meena Lagna kuja is placed in 4 th house with parvarthana yoga with mercury placed in second house.does kuja dosham applicable. Kuja gives good results in Mahardasha. In navamsa kuja placed in 10 th house with sun

Sir, My Lagna is vrushaba lagnam 9th & 10th houses are of lord shani, who is raja yoga karaka. but as per my chart he is in 7th house vruchika rasi with lord Buda in conjunction. Will the shani maha dasha suit me?