From the information in the article I linked to above:
"To avail of this reward, customers must first purchase the Apple Watch and manually register for the Zopper Wellness Program, which is free of charge. This offer is available at all Apple Premium Resellers in India, including Invent, Unicorn, and others. However, it’s important to note that this offer will be exclusively available at offline outlets of Apple Premium Resellers and may vary depending on the city and store. Purchases made through the official Apple website, Amazon, Flipkart, or other retailers will not be eligible for this offer."
If you have further questions, contact HDFC Ergo or Zopper. It's their program, not Apple's.
Regards.