Raja yogas are Shubha ('auspicious') yogas that give success and a grand rise in career or business, and a greater degree of financial prosperity particularly during the dasha of the planets that give rise to Raja yogas. However, these results get adversely modified by the presence of other Ashubha ('inauspicious') Arista yogas.Basically, the Yoga or Raja yoga-causing planets during the course of their respective dashas confer their most auspicious results if they happen to own the lagna-bhava (the Ascendant) or the Suta-bhava (the 5th house) or the Bhagyasthana (the 9th house); the person remains healthy, wealthy, happy and successful enjoying yoga and Raja yoga results in case the lagna, the 3rd, the 6th, the 8th, the 9th and the 12th houses counted from the lagna are also not occupied by any planet, and the kendras (quadrants) are occupied only by benefic planets.
Raj Yogas: The Lagna lord itself in lagna, with 4th house , with 5th house, Lagna with 9th hoses or with 1oth house. 4th lord with 5th house, 4th lord with 9th house or 4th, 4th lord with 10th house
5TH lord with 9th house or 5th lord with 10th house
9th lord with 10th house or 9th lord with 4th house
If there is present a relationship (combination, bidirectional vision or exchange of zodiacs) between two or more than two planets (out of which atleast one should be the lord of 'Kendra' & the other should be the lord of 'Trikon') in a birth chart than these planets are said to be constititing a 'Rajyog' in Kundli or birth chart. This 'Raja Yoga' in Vedic Astrology is said to give benefits to the person concerned related to the houses in which this 'Raj yog' has taken place or related to the houses of which the planets constituting 'Rajyog' are having a lordship. Rajyog in Kundli doesn't necessarily mean becoming a king. Usually its benefits are observed in a person's life when there is mahadasha of one planet and the antardasha of another planet in the person's life, provided both planets are constituting Rajyog in some way in the person's birth chart.