What date did the DVD for season six come out in region 2?
CREATE TABLE "table1_1067134_1" (
  "dvd_name" text,
  "num_of_ep" real,
  "region_1" text,
  "region_2" text,
  "region_4" text
);
SELECT "region_2" FROM "table1_1067134_1" WHERE "dvd_name"='Season Six';