Sun in 10th house in Astrology is perhaps the best placement of all the houses, even better than the 1st house, as the 10th house is of career and public service, a person with a well-placed Sun rises in life to a high status like CEO or chairman of a company, this also gives an ability to work in the government and politics. Since this is the strongest Kendra house, the Sun gets bonus qualities if well placed in a good sign.
The 10th House in Astrology shows your image in the outer world, as a place of work and community, as it’s opposite to the 4th house which is home, your private life. It rules career too, but only holds 30% of the truth about your career. In Greek astrology, they give a major emphasis on the 10th house and its lord or the planet sitting in the 10th house to determine your career, but this is not true, why you ask? Because Greek only relies on 1 chart, your basic birth chart, and, sometimes eastern astrologer, too, relies on the same chart. But, there is a bigger depth to this house.
In Eastern astrology, there are many (Divisional) charts that show a detailed analysis of a person’s life, which can be career, marriage, children, health, travel, etc. The divisional chart that rules the career is called (D-10 chart) or Dashamsa chart in Eastern astrology. (We’ll talk about it later) But a career is also seen from 2nd, 6th, and 7th house, too. 7th house is 10th from the 10th house, which becomes the career of your career house.
The 10th House in Vedic Astrology represents the working years, the time of life one is fully productive and career-oriented. The 10th house represents the source of livelihood and everyday work. It is the most active house and is generally connected with how we do things and how the outside world labels us. The 10th house corresponds to the 2nd part of the legs, the knees. Capricorn corresponds to the 10th house. Saturn, its ruler, signifies routine work, and the movable property adds to the active nature of the 10th. The element of Earth ties the 10th house down to mostly physical and materialistic matters.
Sun in Vedic Astrology represents the soul. This can be read in the most flexible and general sense of the word. The word soul is used for the deepest and truest nature, for the ultimate sense of identity, inspiration, and aspiration. Surya signifies one's essential attributes - the sense of self, ego, self-esteem, a sense of purpose, and so on. Energies and conditions that arise from the Sun's placement in a horoscope, along with the influences that the Sun receives, will be experienced in life as deep, long-term trends and processes that impact one's life as a whole.
Note: The degree of auspiciousness and inauspiciousness will depend upon a complete analysis of the horoscope (birth-chart).