Who is Yosantha?
There is no reliable public record of anyone notable named Yosantha.
The honest answer
As of now, there is no widely documented public figure, historical person, or established concept clearly known by the name ‘Yosantha’. It does not map onto a notable entry in general reference sources, so the most truthful thing to say is that the name is unverified rather than to invent a biography for it.
That gap matters. Making up details about a real-sounding name is how misinformation starts, especially when the name might belong to a private person who never asked to be written about.
What the name could be
‘Yosantha’ resembles names rooted in South and Southeast Asian languages (Sinhala, for instance, has names with similar sounds), so it may well be a real personal name. Real does not mean public, though: most people who carry a given name leave no trace in encyclopedias.
How to actually find out
If Yosantha is someone you met, follow, or read about, the surrounding context (a company, a sport, a city, a social platform) is the fastest path to a real answer. Without it, the responsible reply is simply: not enough information yet.