Excise duty exemption for manufactured goods where Indian ownership, indigenous design and specified foreign patents are established and certified. Exemption from excise duty applies when goods are manufactured by a wholly Indian owned company, designed and developed by that company, and patented by it in India and in specified foreign jurisdictions; the manufacturer must produce a pre production DSIR certificate to the jurisdictional Commissioner and follow the Commissioner's prescribed procedure. The exemption is time limited after commencement of commercial production.