try to find essay on google..rather considering here

no hr ask to speak on 12 min

whatever  topic u have been given.. speak as much as u can 
bt be logical ... if they say for 12 minutes ,, no issues 
speak till u can ,,, then simply say, that is all i can 
speak on b.p.o. n thanks or thanku vrymuch .,,'
by doing this they just check ur grammar, creativty, 
knowledge .. u can ask for a minute to prepare ,, or as per 
rules ...before speaking on topic ...
bbye ,, hope it helps u..