“Nishar” as a word is not a standard Jain religious term in the scriptures, and it is not commonly listed as a specific Jain caste or community name in Jain tradition.

From a Jain point of view:

• Jainism is a dharma (religion), not a caste.
• Anyone from any community can be Jain if they accept and follow Jain principles (ahimsa, anekant, aparigrah, vrat, etc.).
• Many different jatis/communities follow Jain dharma (Oswal, Porwal, Vania, Saitwal, etc.), but these are social names, not required by Jain shastra for being a Jain.

So:

• If there is a community somewhere locally called “Nishar”, they can be Jain if they follow Jain dharma, but “Nishar” itself is not a Jain scriptural category.
• For government or caste‑list questions (SC/OBC/etc.), that is a secular classification, not defined by Jain religion, so Jain scriptures do not give an answer for that.

If you meant some other spelling (like Nishad, Nisar, etc.) or a specific region, it is best to ask a local Jain leader or temple in that area for exact social details.

You can read more about how Jainism looks at caste and community here