i bought my i phone from Australia and i am using this in India , My home button is not working...

No authorized service provider will touch this phone in India, or help you in any way. One of the downsides to purchasing an iPhone in a country you don't live in or intend to use the phone in.

You'll have to fly back to Australia for all warranty/service work...you can't mail the phone to Apple, as Apple does not accept International shipments.

You can also use Assistive touch to replace a faulty Home button:

http://support.apple.com/kb/HT5587