Do tattoos conflict with six-pointed stars and six-character mantras?

Can't say conflict, but the two have nothing to do. The six-pointed star is the divination symbol of Judaism, while the six-character mantra originated in India, and the Buddhist language is Sanskrit, so there is no relationship between them. If you are a believer in these two religions, this is not recommended. If you are not, it may not matter. Buddhism is tolerant, but Judaism is xenophobic and will treat you as a heretic, so there should be no problem as long as you avoid Jews. . .