You may try this formula:
=IFERROR(INDEX(Sheet2!C7:G22, MATCH(B6, Sheet2!B7:B22, 0)+IF(A6="2026 Rates",6,IF(A6="2027 Rates",12,0)), MATCH(C6, Sheet2!C$6:G$6, 0)), "Rate Year Not Found")
References: