Export proceeds realisation obligation: failure to provide proof triggers immediate duty credit liability and interest. Prescribes a Legal Undertaking/Bank Guarantee for DEPB and Chapter 3 incentive scrips obliging the exporter to realise export proceeds equal to the FOB value endorsed on scrips, to furnish periodic statements and Bank Realisation Certificates, and to pay forthwith on Government demand sums equal to duty credit issued for non-realisation. Failure to produce BRC within 12 months triggers payable duty-credit amounts, with further liability to pay within 60 days plus prescribed interest; the Government may deduct unutilized scrip credit and pursue all other statutory remedies.