Let’s look at important things here –
Moon - Moon represents Mind, Emotions, Mother, Local Government, Peace of Mind, Home Environment, Water, Milk etc.
Vishakha - Vishakha is nakshatra of counselors and guides. It is also nakshatra of split or partition or different direction. For more information on Vishakha Nakshatra, please check this link - https://www.astrosaxena.com/vishnaksh.
Libra - As Vishakha is a part of Libra, Libra sign and its representations also become important. Libra is the 7th sign of Zodiac Belt, hence it represents the energy and things related with 7th house of horoscope, i.e. Market Place, Business, Partnerships, Relations etc. Libra is sign of Balance, i.e. striking the Balance between 2 parties/ideologies or even at personal level between our own dilemmas. It is sign of Peace and Diplomacy. And this is what we are seriously looking for after the conflicts and disagreements of Virgo, i.e. Peace to prevail. At personal level, Libra is seen as sign of Relationships. Libra is consisted of 2 and half Nakshatra named Chitra, Swati and Vishakha. Libra's lord is Venus only.
Scorpio - As Vishakha is a part of Scorpio too, 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.
Jupiter - As Jupiter rules Vishakha, Jupiter's position and dignity is important to know about the overall functioning of any planet in Vishakha.
Venus - As Venus rules Libra, Venus position and dignity is important to know about the overall functioning of any planet in Vishakha/Libra.
Mars-Ketu - As Mars-Ketu rules Scorpio, Venus position and dignity is important to know about the overall functioning of any planet in Vishakha/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 Moon in Vishakha Nakshatra – Moon gets debilitated in Vishakha. It is debilitated at 3 degree Scorpio/Vishakha. Although Saturn gets exalted in Vishakha but it is at 20 degree Libra/Vishakha. Actually, no planet is exalted in Scorpio. If we understand why Moon is debilitated in Vishakha then majority of this placement will be understood.
Vishakha is represented by Forked Branches which show split directions. Moon represents Mind. So, when Moon is in Vishakha, these people always get into a situation of choosing 1 direction among the choices available and that decision making can be tough for them. It can also give them split views on almost everything in life and mind is unable to decide which view is correct. But things are still little better when Moon is in Libra/Vishakha as with time, these people can improve and develop a way to decide matter. They can also be a good counselor or mediator among warring parties but as it goes closer to Scorpio/Vishakha, problems increase. Scorpio is sign of chaos and instability. Mind wants to live in peace and last thing you can expect in Scorpio is peace. Hence, Moon is debilitated in Scorpio/Vishakha for double reason of chaotic environment (Scorpio) and indecisiveness (Vishakha).
But there are still ways by which these people can find peace. Moon in Libra/Vishakha finds peace through relationship, business, interacting with others and Moon in Scorpio/Vishakha finds peace through research, occult, psychology and diving into dark unknown sides of this Universe. Both positions can create a counselor in later life. In Libra, a relationship counselor, mediator or diplomat/peace maker, whereas in Scorpio, it can be occult or psychology related counselor. Mother can be strict in Scorpio/Vishakha with very little emotions whereas in Libra/Vishakha, she can have a very balanced nature. Overall, a tough nakshatra for Moon to be in and things improve with age. Meditation is the only solution.
Role of Jupiter – Jupiter placement is important to guide Moon in right direction, being Vishakha's lord.
Role of Venus - Likewise, Venus placement is important to guide Moon in right direction, being Libra lord.
Role of Mars-Ketu - Also, Mars-Ketu placement is important to guide Moon in right direction, being Scorpio lord.
Other Factors – And of course, we need to consider conjunction, aspects, house lordship, house position and dashas etc to know the exact results of Moon in Vishakha. So, we always need to take a holistic view of chart rather than just 1 planetary position.
Conclusion – So, this is how I see Moon in Vishakha can work in a chart.