Whatsapp Riddle: 1 3 5, 2 4 ?

Whatsapp Riddles are getting challenging as days are going by. The riddle no longer have the most obvious answer. You must have surely received this riddle at least once by now on WhatsApp or Facebook. Solve thisĀ if you are a genius! 1 3 5 2 4 ? And answer is not 6. So were you