jain comes under which caste

Jain does not come under any one caste.

• Jainism is a separate religion (dharma), not a caste.
• Jains can be born in different social groups (Oswal, Porwal, Agarwal, Khandelwal, Vania, etc.), but these are community / jati names, not a single “Jain caste” for everyone.
• Jain scriptures do not give spiritual importance to caste; progress depends only on right faith, right knowledge and right conduct, not on birth.
• Both Digambar and Shwetambar traditions agree that caste has no value in deciding who can follow the Jain path or attain moksha.

You can read a simple explanation on this topic here