Parvata Yoga is a benefic yoga that brings many good qualities for the natives of this yoga.
Parvata yoga will make natives more optimistic, lucky, and happier in marriage, loving, affectionate, more spiritual, sharp in communication and creative intelligence, and ultimately, mentally strong.
This Yoga arises when either of the 5 conditions listed below is satisfied.
Rules
There are a couple of rules that guide the formation of Parvata yoga, one of these conditions or rules must be in effect before this yoga can be formed.
Parvata yoga arises when:
1) Benefic planets occupy Kendras.
2) The 6th and 8th houses are empty or unoccupied.
3) 6th and 8th houses are occupied by benefic planets only.
4) (For ex-Jupiter) Moon is in Aries ascendant, Mercury and Venus in Libra will produce this yoga.
5) The lords of Lagna and the 12th are in mutual Kendras.
These are the rules or conditions that govern the formation of Parvata yoga.
Exceptions
1) There is an exception to the 5th rule above for the Kumbha Lagna. Supra cannot bring good results if the lord of the 12th and the Lagna happen to be Saturn.
2) Also, in the case of the 6th and 8th houses being occupied, that makes it easy for the native to be influenced by evil people and susceptible to debt (even when 6th and 8th are occupied by benefics). So it is better that they are empty and unoccupied.
Comments and other details
Parvata yoga, though good in its effects, is not as strong as some other yogas, therefore it may not be able to reduce the effects of some more powerful malefic yogas. It may give financial stability but it may not be strong enough to give extensive power e.g political power on a large scale.