Yes, it is possible to avoid hell, even if someone becomes Jain later in life after doing many harmful actions before.

In Jain Dharma, karma is not fixed forever. Whatever bad karma has been bound by past actions can be weakened, reduced, and purified through:

• true repentance
• right faith and right knowledge
• stopping हिंसा and sinful activities
• following vows as much as possible
• pratikraman, repentance, and आत्मशुद्धि
• living with ahimsa, truth, restraint, and non-attachment

What matters most is the present inner change and the new karma being stopped. If a person sincerely turns toward Jain dharma, stops creating severe हिंसा, and practices purification, they can greatly improve their spiritual future.

But Jainism also teaches that:

• past karma does not disappear instantly
• serious bad karma can still give results
• so one should not become careless and think, “Now I am safe no matter what.”

So the right understanding is:

• Yes, change is possible
• yes, hell is not inevitable
• but serious repentance and disciplined conduct are necessary

In simple words: A person who sincerely turns to Jain Dharma later in life can still save themselves by purifying conduct and reducing new bondage of karma.