You inner loop should iterate over the second item of the tuple:
list_movies = [('Spiderman 3', ['John', 'jake','Ronald']),('Gravity',['james','jake','john','gerald']),
('Terminator',['Anne','Johnny','Peter','Ronald','Neville'])]
count2 = 0
for (movie,viewers) in list_movies:
count = 0
for (name) in viewers:
if name != '':
count += 1
if count > 3:
count2 += 1
print("last movie viewers: %d" % count)
print("count of movies having had more than three viewers: %d" % count2)