CREATE TABLE table_73683 ("Season" FLOAT, "MLS Regular Season" TEXT, "MLS Cup Playoffs" TEXT, "Lamar Hunt U.S. Open Cup" TEXT, "CONCACAF Champions Cup / CONCACAF Champions League" TEXT)

What was the season when mls regular season was 6th, east (9-11-10)?
SELECT "Season" FROM table_73683 WHERE "MLS Regular Season" = '6th, East (9-11-10)'
SELECT "Season" FROM "table_73683" WHERE "MLS Regular Season" = '6th, East (9-11-10)'