CREATE TABLE table_16647 ("#" FLOAT, "Episode" CLOB, "Air Date" CLOB, "Rating" CLOB, "Share" FLOAT, "Rating/Share 18\\u201349" CLOB, "Viewers  ( m ) " CLOB, "Timeslot Rank" FLOAT, "Night Rank" CLOB, "Overall Rank" FLOAT)

what's the night rank with viewers (m) of 6.63
SELECT "Night Rank" FROM table_16647 WHERE "Viewers (m)" = '6.63'
SELECT "Night Rank" FROM "table_16647" WHERE "Viewers (m)" = '6.63'