Meghalaya GST rules amend refund forms and GSTR-9 reporting, tightening documentation, ITC entries, and audit filing rules. Substitutes and inserts multiple Statements in FORM GST RFD-01 to prescribe documentary formats for refund types (ITC from inverted tax structure; export refunds with/without tax; supplies to/received from SEZs; deemed exports; change in place of supply). Amends FORM GSTR-9 to add FY-specific ITC and transaction reporting entries for FY 2017-18 and FY 2018-19, mandates prior filing of GSTR-1 and GSTR-3B, permits optional net reporting of certain tables for those years, and revises auditor certification and reconciliation statement provisions in GSTR-9C.