Let’s look at important things here –
Mercury - Mercury represents communication skills, marketing, calculative ability, younger siblings, hobbies, skills with hands, intelligence, quick decision making, logical thinking, youthfulness etc.
Anuradha Nakshatra - It is a nakshatra of following heart's desires or being devotional about something or someone. It is also related with mystical side of life. For more information on Anuradha Nakshatra, please read this - https://www.astrosaxena.com/anunaksh .
Scorpio - As Anuradha is a part of Scorpio, Scorpio sign and its representations also become important. Scorpio is the 8th sign of zodiac belt, hence it represents the things and energy related with 8th house of horoscope like Sudden Events, Secrecy, Dark World, Occult Science, Research, Inheritance, Serving Others, Taxes etc. Besides these things sign of Scorpio also represent transformation, means changing the whole nature upside down. This is one sign which is favorite of every Astrologer, because it has maximum secrets, so every astrologer gets maximum scope of researching. This is sign about which no one can tell with precision that what will happen to the planets in it, as it is sign of secrecy itself. Wherever Scorpio falls in your chart, you may have had biggest challenges in making things related with that house more stable. Scorpio is also one of those unique signs which has 2 rulers, i.e. Mars and Ketu. In Western Astrology, Pluto also co-rules Scorpio. All this makes Scorpio a chaotic sign. Scorpio consists of next set of 2 and half nakshatras, i.e. Vishakha, Anuradha and Jyeshtha.
Saturn - As Saturn rules Anuradha, Saturn's position and dignity is important to know about the overall functioning of any planet in Anuradha.
Mars-Ketu - As Mars-Ketu rules Scorpio, their position and dignity is important to know about the overall functioning of any planet in Anuradha/Scorpio.
Houses Involved – Also, we can’t afford to forget the houses involved as a planet can be ruling different houses and sitting in different house for every person as per ascendant and planet’s position. To know overall affect, we have to consider the houses involved as those areas of life are being impacted.
Interpretation of Mercury in Anuradha Nakshatra – Mercury is in enemy sign here but in friendly naksatra. At the same time, that friend is also Saturn which is practically not a friend of anyone. So, it means that it is not one of good positions of Mercury. The common theme around Mercury and Anuradha Nakshatra is that both are connected with desires and interests. Mercury represents our interests and skills. Anuradha represents following desires. So, we can say that they are desire oriented or we can also say that they follow their heart's desire in matters of their interests, skills or business. As all nakshatras of Scorpio are somewhere connected with occult and mysticism, the option of following occult interests are always on. As Mercury itself is karaka of Astrology, Mercury in any nakshatra of Scorpio sign gives interests in Astrology.
At the same time, it shows instability in relations if Mercury is a relationship oriented planet for a person. Control and Dominance can be main reason behind that instability. So, this planetary placement can function best when person follows his desires in matters of business and interests but it can bring troubles in relationship.
Role of Saturn – Saturn placement is important to guide Mercury in right direction, being Anuradha's lord.
Role of Mars-Ketu - Likewise, Mars-Ketu placement is important to guide Mercury in right direction, being Scorpio's lords.
Other Factors – And of course, we need to consider conjunction, aspects, house lordship, house position and dashas etc to know the exact results of Mercury in Anuradha. So, we always need to take a holistic view of chart rather than just 1 planetary position.
Conclusion – So, this is how I see Mercury in Anuradha Nakshatra can work in a chart.