The rumor is that new iMacs would hit the Indian market today. Though there are some sources who are still not sure about the rumour. They are saying that it will take about 20 days before iMac land in India.
The sources have also informed that macs will launch in Indian on same day as in US but stocks will hit the market a little later than US.
This has been a trend since the last few years. And this is applicable only to the Macs, and not other iOS devices. When Apple announces iOS devices and provides a launch date, the products launch on that date itself.
If you are hoping that you will get your hands on iMac from the official website then also you may have to wait for some time.