Elections in India are strange. The one demographic that makes the most noise is the one that votes the least ( 44.73% in Bangalore South, for instance). Disappointing as it is, what with all the talk about voter activism, the apathy is well entrenched.
The other reason, I believe, for the low turn-out is the difficulty in getting to actually cast your vote. Every eligible voter is assigned to a polling booth and has to apply to be registered as a voter. Moreover, if you have moved in to a location within the last six months, you have no chance of voting at your new address. At least three people I know were not allowed to cast their votes because they had moved to a new city recently.
A possible solution is to allow anyone to vote in any part of the country as long as they have a valid ID and an address proof that proves he/she is an Indian resident. After all, the place one is currently staying in is what matters most. It will allow the swathes of migrant populations an opportunity to cast their votes.