Mercury rules 12th and 3rd house is in 10th house in Aries

Mercury in the 10th house of a native's vedic horoscope is considered auspicious as it is associated with career, reputation, and achievement. Aries is a sign associated with courage, leadership and drive. Thus, when Mercury is placed in Aries sign in the 10th house, it gives a boost to the native's career and professional life.

This placement suggests that the native will be a natural communicator and an excellent strategist. They are likely to have a quick wit and sharp intelligence which would help them make important decisions at work. They may also have an interest in writing, journalism or other forms of communication.

The position of Mercury in Aries in the 10th house also suggests that the native will have leadership qualities and an entrepreneurial spirit. They may be self-starters and driven to succeed in their chosen field. However, they may also have a tendency to be too impulsive and may need to learn to balance their enthusiasm with practicality.

Overall, this placement is positive for the native's professional life, and they are likely to achieve success and recognition in their career due to their intelligence, communication skills and leadership abilities.