With the Nougat update for the Galaxy S7 and Galaxy S7 edge, Samsung officially confirmed that Samsung Pay would soon be coming to India. There has been no specific date for when the service would actually launch, but Samsung is now letting users sign up for early access to Samsung Pay. Supported devices include the Galaxy Note 5, Galaxy S7 and S7 edge, the Galaxy S6 edge+, and the Galaxy A5 (2016) and Galaxy A7 (2016), all of which were updated with the Samsung Pay app through recent software updates.
Currently, Samsung is offering support for MasterCard and Visa credit and debit cards from Axis, HDFC, ICICI, SBI, and Standard Chartered banks, with support for Citibank coming soon. This snuffs out an earlier rumor that said Samsung would launch the service with support for only American Express cards. Registration can be done at the source link; should you find the website gives you an error upon submitting your details, simply keep trying until the process goes through. The Samsung Pay website also seems to be problematic on Chrome, so make sure to try out other browsers or complete the registration on your phone.
There is no mention of when the early access program will begin, but Samsung will be sending out an email to registered users when it does. The company will hopefully add support for the Galaxy S6 and S6 edge once the service goes live; upcoming devices like the Galaxy S8 and the A (2017) series (which is yet to launch in India) should also support Samsung Pay, but nothing is confirmed at this point.
Thanks, Shivam!