what's the night rank with viewers (m) of 6.63
CREATE TABLE table_16647 (
    "#" real,
    "Episode" text,
    "Air Date" text,
    "Rating" text,
    "Share" real,
    "Rating/Share 18\u201349" text,
    "Viewers (m)" text,
    "Timeslot Rank" real,
    "Night Rank" text,
    "Overall Rank" real
)
SELECT "Night Rank" FROM table_16647 WHERE "Viewers (m)" = '6.63'
Below are sql tables schemas paired with instruction that describes a task. Using valid SQLite, write a response that appropriately completes the request for the provided tables. ### Instruction: what's the night rank with viewers (m) of 6.63 ### Input: CREATE TABLE table_16647 (
    "#" real,
    "Episode" text,
    "Air Date" text,
    "Rating" text,
    "Share" real,
    "Rating/Share 18\u201349" text,
    "Viewers (m)" text,
    "Timeslot Rank" real,
    "Night Rank" text,
    "Overall Rank" real
) ### Response: SELECT "Night Rank" FROM table_16647 WHERE "Viewers (m)" = '6.63'