Provisional assessment for imported used cranes requires provisional duty, bond and engineer valuation pending RTO registration. Provisional assessment is required for imported old and used cranes to prevent misdeclaration of year and capacity. Importers must pay duty on value ascertained by a Chartered Engineer at first check, submit a bond for the entire value and potentially provide a bank guarantee; finalisation follows submission of a matching RTO registration certificate, while mismatches will prompt revenue-protective action.