If you later want to change your plan (during the advance rental period), they won't let you do it - unless you agree to forfeit the entire advance rental and start paying from scratch for the new plan. I took the advance rental option - personally, I wouldn't do recommend it for the before mentioned reason. Plus, if you are unhappy with the service for any reason, you really can't do much other than cancel and wait a few months for a refund. If you are fairly sure of the service in your area (neighbors etc. happy with airtel) and the plan meets your needs, it might be worth it - I got free installation and modem with the advance rental as well.
