I'm searching for this Jataka where a monk is brought by The Buddha to heaven, and then to hell, where the monk sees a vacant place(?) in hell and asks a hell officer about it. The hell officer answered that he was waiting for a heaven inhabitants who will reborn in hell. Hearing that, he monk was shocked and trained harder to be free from the samsara.
Maybe anyone here knows about that Jataka? Thank you
According to this entry from the The Princeton Dictionary of Buddhism by Buswell & Lopez, that monk is probably Sundarananda, often referred to as Nanda (not to be confused with Ananda):
After going to heaven, the Buddha takes Nanda on a journey to hell, where he shows him the empty cauldron that awaits him after his lifetime in heaven. After his enlightenment, Nanda came to the Buddha to inform him of his achievement and to release the Buddha from his promise of celestial maidens. It was because of his great will to control his passions that Nanda was deemed foremost in self-control.
Unfortunately, the entry doesn't cite any source, only contains a brief mention of the poem Saundarananda by Aśvaghoṣa, where Sundarananda is the protagonist. I've skimmed through the poem - it dedicates one lengthy chapter to describe Nanda's journey to heaven, but nowhere does it depict him going to hell with the Buddha.
I found other mentions of him in chapter 5 of the Śūraṅgama Sutra, but only in the version with commentary by Master Hsuan Hua (宣化). Here is that piece:
After they finished touring the place the Buddha took his cousin down to the hells. There they saw two ghosts heating a cauldron of oil. One of the ghosts was sound asleep and although the other one was awake, he didn’t have his eyes open. Nanda sized up the situation and thought to himself, “These ghosts are suppose to be tending the fire under that cauldron, but they’re not doing their job at all. Boy, are ghosts lazy!” Then he meddled a bit and nudged one, saying, “What are you doing this for?”
The little one’s droopy eyes popped open and glared at him. “What’s it to you?” he snapped.
”I just wondered,” said Sundarananda.
”You gotta know, huh? Okay, I’ll tell you. The Buddha’s got a cousin who’s cultivating the blessings of people and gods. He’s going to get born in the heavens and enjoy 500 years of heavenly blessings before he falls. Once he topples, however, he’ll come all the way down to hell and when he gets here, we’re supposed to have this pot hot. He’s to be deep-fried alive.”
Sundarananda was horrified and his hair stood on end. He suddenly understood the whole picture and thought, “Those heavenly maidens are ravishing, but 500 years of bliss with them isn’t worth it if I’m eventually going to end up in a pot of boiling oil. I’d better follow the Buddha, leave home, and be a monk.” So he forgot about Sundari and left home.
One thing's for sure: this story is not a Jataka.
Such does not exist, at least not as a Jataka delivered by the Buddha's own disciple Sangha, good householder. And furthermore, Jataka-stories are stories about the Buddha's life before his last birth where he gained awakening. So they are merely fairy tales of the "Dhamma-trader" (Ud 6.2). There are many 'fake' tales around and it's good to seek within the tradition, not outwardly and on common market and entertainment places, good householder.
As for falling to hell or heaven, here related: Avannaraha Sutta: Dispraise. So one should take care, especially in relation with the Gems. Ignorance of wrong actions do not prevent consequences from arising.
