It looks like the Samsung Galaxy S8 Oreo beta program has entered its second phase, as the beta build is now available for units in India.
You can register through the Samsung Members app (Home->Notices->Register for Galaxy Beta Program). Once that is done, you can download the update by heading to Settings -> Software update -> Download updates manually.
The update weighs in at around 1,395MB.
It’s worth mentioning that Samsung hasn’t yet officially announced that this is the second phase for the Galaxy S8 Oreo beta program.
Previous reports said the second wave of countries would include Germany, Spain, France, Poland along with India and China. There’s currently no information on whether or not the program has been expanded to these other regions as well.