U can decide NOT to VOTE

Section 49-O of the Constitution of India

The constitution, as per the 1969 act, section"49-O", says

 “ a person can go to the polling booth, confirm his identity, get his finger marked and convey the presiding election officer that he doesn't want to vote anyone!
”

This is called "49-O".
What happens if I say “No Vote”:
If the no. of ‘No VOTEs’ is larger than the number of votes by which a candidate has won, then
1.  The polling shall be cancelled
2.  There shall be a re-polling
3.  The candidature of all the contestant shall be cancelled.
Source
http://www.hindu.com/2006/04/04/stories/2006040412450100.htm