Literal meaning of Yoga is addition in Vedic or Indian astrology. Astrological yoga is formed by two or more planets in an indian horoscope. There are three types of planets in Indian Vedic astrology which can be considered as functional, malefic and neutral. If there is yoga between two or more benefics.These benefics join hands to do good for the native. This yoga ensures success in undertakings-health, material gains, personality, righteous conduct etc.So a benefic yoga leads great strength to a birth chart.

When the Yoga is between a malefic and a benefic, malefic will spoil the benefic effect of the benefic. It is called Arishta yoga, Arishtha, misfortune in Indian astrology.Arishtha yoga includes worries, miseries, troubles, and discords etc.Arishta removes the vitality of any horoscope. Natural benefic and malefic planets are also taken into consideration for information of yoga or Arishtas.Even two malefic planets joining or mutually aspecting may spoil or nullify the significance of the house/houses.

One of the most popular yoga in Indian or vedic astrology is Gaj Kesari yoga.Gaj Kesari yoga is commonly understood as “if Jupiter is in kendras from the moon, Gas Kesari yoga is formed.Gaj Kesari yoga assures long life span, high reputation even after death, higher learning,intelligence,passionate and emotional behaviour. Native can address others with wisdom and foresight. Native is able to achieve anything by his/her own velour etc.If will be seen that where Jupiter or the moon or both are functional malefics, the yoga will get modified accordingly and will not confer very good results.

In Indian Vedic astrology, the Moon ascendant has been given equal importance as is given to the ascendant. The reason is that the moon is ruler of mind. It should be taken into consideration that if Jupiter shall conjunct or be in Kendras with the moon or aspect Moon, he shall ward off evils, shall incline the person to religion, learning, righteous conduct etc.Maharshi Parashar is of the view that if Jupiter is in Kendra from the ascendant, it portends similar results. Great Vedic astrologer Maharishi Parashar in his famous work “Brihat Parashar Hora Shastra” has given a sloka on Gaj Kesari Yoga. Should Jupiter be in an angle from the ascendant or from the moon and be conjunct or aspected by a benefic avoiding at the same time debilitation,combustion,an inimical sign, Gaj Kesari yoga is formed.

According to Maharishi Parashar, Kendra position of Jupiter should be seen not only from the moon but also from the ascendant. Another important condition added by Maharishi Parashar is that Jupiter must conjunct or be aspected by a benefic. Aspect of a benefic or conjunction with it shall further strengthen Jupiter. There is no denying the fact that if Jupiter is otherwise strong and not aspected or conjunct by a benefic, he is fully capable of fructifying the yoga. When Jupiter is combust, debilitated or in inimical sign, it is less effective to do good to the native. Other condition which shall be taken into consideration are-
Jupiter must be a functional benefic for the ascendant. So, Great astrologer Maharishi Parashar has ruled out Gaj Kesari yoga for Taurus, Gemini, Cancer, Virgi, Libra, Capricorn and Aquarius ascendants.
Jupiter must not be in 6th, 8th, 12th houses.

The Moon Should also be strong. It should be strong, have Paksha bala and should not be debilitated etc.If order to cause fructification of yoga in case yogas is from the Moon. Position of the Moon from the ascendant is also important i.e. the Moon should not be in 6,8,12 houses from the ascendant. It should also be taken into consideration that if Jupiter is in an angle from the ascendant or from the Moon in own sign or exaltation, the combination shall be called by the name of Hamsa yoga