Hi, I recommend that you check out the foundation fighting blindness website and sign up for their newsletter. I doubt there’s a better source of information regarding research. Good luck.

There is currently no treatment for Stargardt's.

The link you sent for the Mayo clinic is for dry mac degen. And even then, under treatment, is says "*As of now, there's no treatment for dry macular degeneration. However, there are many clinical trials in progress. If your condition is diagnosed early, you can take steps to help slow its progression, such as taking vitamin supplements, eating healthfully and not smoking.*"

I don't know anything about the link to the place in India, and was not able to find any reviews of the place. But stem cell treatments are bleeding edge treatments, and there has already been cases (in the US) where clinics injected stem cells into their patients who lost more vision. There are a LOT of places that are willing to take your money, regardless of how dangerous a treatment could be.

https://www.washingtonpost.com/national/health-science/this-clinics-experimental-stem-cell-treatment-blinded-patients-four-years-later-the-government-is-still-trying-to-shut-it-down/2019/04/03/432d6d04-ff2f-11e8-83c0-b06139e540e5_story.html

https://www.retina-specialist.com/article/court-orders-halt-at-florida-stem-cell-clinic-that-blinded-three-patients-after-treatments