CREATE TABLE table_1140090_6 (circuit VARCHAR2, race_name VARCHAR2)

What circuit is the Vi Rhein-Pokalrennen race in?
SELECT circuit FROM table_1140090_6 WHERE race_name = "VI Rhein-Pokalrennen"
SELECT "circuit" FROM "table_1140090_6" WHERE "VI Rhein-Pokalrennen" = "race_name"