* A nickname or shortened version of a longer name: Like "Sil" for "Sylvia", "Silica" for "Silvana", or "Silas" for "Silas".
* A made-up name: People sometimes create unique names for their children.
* A name from a specific culture or language: It's possible the name is used in a particular region or language that isn't widely known.
To find out more, you would need additional context:
* Who is "Silka"? Knowing the person's background might help determine the origin.
* Where did you encounter the name? A specific location, book, or other source could provide clues.
Without more information, it's difficult to definitively say where the name "Silka" originates.