can humans go to ethar nigode after performing bad Karma
In Jainism, Nigoda (sometimes spelled "Nigauda" or "Nigodh") refers to the lowest form of life, a microscopic and most elementary life-form that exists in a state of perpetual suffering and ignorance. Nigoda beings have minimal consciousness and are considered to be in the lowest state of existence.
According to Jain philosophy, all souls pass through countless births and rebirths in various forms, including as nigoda beings, due to the accumulation and fruition of karma. However, once a soul has evolved into a human form, it is generally not believed to regress back to the nigoda state. This is because human birth is considered extremely rare and valuable, providing a unique opportunity for spiritual advancement and liberation (moksha).
If a human accumulates very bad karma, Jainism teaches that the soul may be reborn in lower forms of existence, such as animals, plants, or even in hellish realms (Naraka). However, a return specifically to the nigoda state is not typically mentioned in Jain scriptures as a consequence for humans, because nigoda is regarded as the starting point of souls' journey and not a destination for regression after higher births like that of humans.
In summary: According to Jainism, after performing bad karma, a human soul may be reborn in lower realms or as lower life forms, but not usually as nigoda beings. The journey is generally seen as a progression away from nigoda, not a return to it.