Excise liability for ready-made garments treated as manufacturer duty, with optional authorization for job worker to pay and comply. Amendment treats a person who gets goods under Chapters 61-63 produced on job work as the manufacturer for excise purposes, making him liable to pay duty in the manner prescribed; the principal may authorize the job worker to pay duty and the job worker so authorised may discharge liabilities and comply with the Rules. 'Job worker' and 'job work' are defined to cover persons performing manufacture or processes on inputs supplied by the principal or an authorised person resulting in goods under Chapters 61-63. The Rules apply to such liable persons as if they had manufactured the goods themselves.