SELECT res::json->'abc'->'c' FROM main WHERE id = 3;
получаю:
             [
             [69, "text_05", "m n o"],
             [4, " text_02", "def"],
             [1, "text_01", "abc "],
             [48, " text_04 ", "jkl"],
             [5, " text_03 ", " ghi"],
             [82, "text_06  ", " pq r "]
             ]