The unit rate will be in revolutions per second. That means divide number of revolutions by number of seconds.
first convert from mixed fraction.
6 2/5 = 32/5 revolutions
2 2/3 = 8/3 seconds
32/5 ÷ 8/3
flip multiply
32/5 × 3/8 = 12/5 revolutions per second
12/5 = 2 2/5 revolutions per second