Refund mechanism for pre-merger ITC claims: taxpayers may file from new GSTIN under 'Any other' to enable refund processing. Taxpayers of the erstwhile UT of Daman & Diu who cannot file refunds for pre-merger periods due to GSTIN migration must file on the GST portal under the 'Any other' category using the new GSTIN, state the intended refund category in Remarks, and attach supporting documents. No electronic credit ledger debit is required on filing. The proper officer will compute admissible refund, may request a FORM GST DRC-03 debit, and upon receipt of proof will issue FORM GST RFD-06 and FORM GST RFD-05. Refunds requiring debit or re-credit must not be filed using the old GSTIN.