If you mean 7xy+2x2y2-8+5x3y6 and you mean ascending degree then the order is:
-8+7xy+2x2y2+5x3y6. The degree is the sum of the exponents of each term. The lowest degree is 0 (no x or y) so -8 is the term with the lowest degree or order. 7xy has order 2; 2x2y2 has order 4; 5x3y6 has order 9.