The 6th house is a malefic house in the ascendant (Lagna) chart, and as such, it is one of the worst places for the Moon to be in. Unfortunately, I have it in my own chart in the 6th house, so I guess I can give a tested and verified experience of how it feels.
Anyways, so the 6th house governs enemies, diseases, debts, service, sudden issues in life (the 8th house also rules that), relations with subordinates and servants, etc.
The Moon is one of the most benefic planets alongside Jupiter, so its placement in the 6th house basically damages the planet to the point it ends up giving negative results instead of positive.
For once, the person is going to have depression, or perhaps severe mental depression – the kind that makes them want to take their own lives. In many cases, the person will suffer due to their enemies, whether that be at the workplace or even in society – here enemies do not mean the kind that will mortally harm the person, but for example, colleagues at work who are simply jealous of the person, or classmates who hate the person and bully him/her for no reason, etc.
Since Moon also denotes the mother of the native, in the 6th house, Moon will naturally get afflicted even if She is not under any planet’s malefic influence or conjunction. As such, the native’s mother might suffer physical health issues and her longevity too may be affected.
If the native is a male, then the person will suffer loss of wealth through females; this is because when Moon is in the 6th house, it gets afflicted due to the house itself, leading to emotional instability. And when there is emotional instability, the person will find it difficult to stay in one relationship, or they may not find the right person who would be suitable for them.
Additionally, if Moon is conjunct any malefic planet including Saturn, Rahu, or Ketu, the person may engage in sinful activities such as engaging in sexual intercourse with girls and women they do not have a marital relationship with – in other words, casual sex.
Any malefic influence further on Moon in the 6th house will cause the person to have an overall weak body which would be prone to diseases in addition to having mental challenges or depression.
However, there are some things to be noted here:
- Moon in Her own sign (Cancer) – if this happens, then Moon will gain considerable power even in the 6th house and will help protect the native from many, if not all diseases. The Moon will also make the person a very powerful individual who will defeat his/her enemies with ease and be feared by their enemies as being someone potentially dangerous himself/herself.
- Moon in Her exaltation (Taurus) – in Her exaltation, the Moon provides protection against enemies and even ill-effects of the 6th house itself, but the person will still make expenditure.
- Moon aspected by (or conjunct with) benefic planets – Moon here will get empowered and will be able to protect the native somewhat from diseases and/or enemies.
- Moon conjunct Rahu or Ketu – the person will have danger to their life in or near watery places as well as due to poison.
The Moon being in the 6th house can cause lifelong depression, and I have personally experienced it unless She is in Her own sign or exaltation, but if the 8th house is not as badly afflicted, the person will find a way to come out of the situation.