In Jainism, the key principle is ahimsa (non-violence). Whether a biscuit is acceptable depends on its ingredients and how it is produced.

• If the biscuit is strictly vegetarian and contains no eggs, no gelatin, no animal-derived rennet, and no other ingredients that involve harm to living beings, it can be considered acceptable from the perspective of ahimsa.
• Many biscuits may include dairy products or other additives. Some Jains are comfortable with dairy, while others (especially among stricter followers in certain communities) may avoid dairy if it involves harm to animals in production. Decide according to your own Jain tradition and guidance from your guru or community.
• Some followers also observe restrictions on consuming root vegetables (mool aahaar) or certain processing aids; in those cases, check whether the biscuit uses ingredients that would violate those rules.
• There are differences between Digambar and Shwetambar practices on exact ingredient norms and fasting/food purity, so you may see slight variations in what is considered acceptable in each tradition.

If you share the exact ingredients list of the biscuit you have in mind, I can help evaluate it more precisely against Jain ahimsa and dietary norms.