CREATE TABLE table_75504 ("Season" TEXT, "Competition" TEXT, "Round" TEXT, "Club" TEXT, "Home result" TEXT, "Away result" TEXT)

Round of 2r, and a Home result of 0-0 has what season?
SELECT "Season" FROM table_75504 WHERE "Round" = '2r' AND "Home result" = '0-0'
SELECT "Season" FROM "table_75504" WHERE "Home result" = '0-0' AND "Round" = '2r'