1.it is to be checked whether the trademark is registered under general category orin specific category.

2.Since You have prima facie found out that no trademark is there for jewellery then you can inform mover email their specific basis of objection.

3.if they fail to produce any counter evindce you may continue to use them till an order of injunction is passed by the court in India or in outside.

1. They might have mentioned under which section you have violated the Copyright Act.

2. If not send a reply to their letter asking them to explain how have you been alleged to have violated the said Act.

3. Till they explain you ground for their sending the said letter (called demand fro justice in legal term) with the said allegation, they are not expected to file any suit against you legally.

Hello,

They have copyright protection in India (believe it from my experience)

Reply them back to the notice, that your rights are not being infringed from your use. Reply to the notice in a strong language.

If they proceed to file a case you will have a god case to defend.

After giving a reply to the notice, you may continue using the said mark in your products.

Regards

Trademark infringement is the unauthorized use of a trademark or service mark on or in connection with goods and/or services in a manner that is likely to cause confusion, deception, or mistake about the source of the goods and/or services.

Infringement may occur when one party, the "infringer", uses a trademark which is identical or confusingly similar to a trademark owned by another party, in relation to products or services which are identical or similar to the products or services which the registration covers. An owner of a trademark may commence civil legal proceedings against a party which infringes its registered trademark. In the United States, the Trademark Counterfeiting Act of 1984 criminalized the intentional trade in counterfeit goods and services.

In many countries (but not in countries like the United States, which recognizes common law trademark rights), a trademark which is not registered cannot be "infringed" as such, and the trademark owner cannot bring infringement proceedings. Instead, the owner may be able to commence proceedings under the common law for passing off or misrepresentation, or under legislation which prohibits unfair business practices. In some jurisdictions, infringement of trade dress may also be actionable.

Here the word Harry Potter may be an objectionable item, you may check as to what is the objection and what is the issue found in the notice issued to you.