Why do landlords in Bangalore demand 10 months rent in advance?

While the common perception is that landlords in Bangalore demand 10 months rent as advance or security deposit, it is seen that most of the landlords are open to negotiating this aspect. They are willing to settle for a lesser amount as advance or security deposit if the tenant is able to convince the landlord of his ability to maintain the premises appropriately, pay the rent punctually etc. As a wannabe tenant, it never hurts to ask.