Ofc Mohammed is the most common name but thats a name common within the muslim community. I have noticed the name Sarah in every country, regardless of race or religion. Or it might be an abrahamic religion thing but thats most of the world atleast.
I suspect other Abrahamic names might make the cut.
India and China each have around 1.4 billion people (source). The next nearest country is the US with ~340 million. Which is a pretty major drop off. So, I would start by looking at common names in either China or India.
The most common Indian names are Hindu names which are isolated in India. Similarly the most common names in China are isolated there. Hence my argument for Abrahamic religions.
Or even common names in both India and China if there’s one
and then try to find one there that is somewhat common in the US too… good luck.