I also sympathise with the notion that TRP is the ultimate barometer for success. It is a great indicator of support for a show and despite immense changes in the way we consume entertainment, it remains central to the health of any Indian television show. However, it would be short sighted to wholly disregard online popularity in the 21st century. International viewers, as you mentioned, do not make up the largest demographic of Bepannaah's online audience; Indians do. I imagine that a large majority of them utilise Voot because it is accessible, high quality and free. Voot has advertisements for almost every single video (at the beginning and in between) for huge brands including Apple. Of all the shows on Voot, I'm sure Bepannaah is at the very least amongst the top 2/3 most viewed. In a world where advertising rules, this is likely significant. The social media buzz and various articles etc are secondary although I'm sure that staying current is considered a positive for any channel in our digital age.
It's also a sad reality, as we all know, that quality content does not equate to ratings. Bepannaah is not the kind of show that provides ratings because most of the time, it makes sense. The extent to which this affects the channel is not something that we can assume, that remains to be seen. It is also not the only Colors show with a fairly low viewership, perhaps something else to consider.