6. Hamura Ōtsutsuki
Hamura Ōtsutsuki was also the son of the Rabbit Goddess, Kaguya Ōtsutsuki. Hamura, like his brother Hagoromo Ōtsutsuki, also inherited the chakra of their mother. He too was also able to use the Six Paths Senjutsu. This enabled him to produce 10 Truth Seeking Orb, just like Hagoromo Otsutsuki. Hamura also had the Tenseigan, which also grants Truth Seeking Orbs.
5. Ten Tails
Ten tails is the combined form of Kaguya Ōtsutsuki and the God tree. The chakra natures of the truth seeking orbs, and the ten tails is the same. So, in a way, the Ten Tails has the Truth Seeking Orbs, as they both have the same chakra natures. Ten Tails is also part Kaguya, and that’s another reason I think it can produce Truth Seeking Balls as well.