Short answer: In Jain practice, you should avoid paan, especially if it contains tobacco or other intoxicants. Jain ahimsa and non-injury extend to all substances that can cause harm or involve intoxicants, so paan with tobacco or other stimulants is not appropriate. If paan is plain betel leaf with areca nut but no tobacco, many Jain authorities would still discourage it because areca nut is a stimulant and its use is generally avoided in strict Jain conduct. Traditions (Digambar vs. Shwetambar) may differ slightly in emphasis, but the core principle is to minimize harm and intoxication.

You can read more here