"There is only one word that I want."
Translation:Hanya ada satu kata yang saya mau.
In this sentence, you can only use "hanya ada".
In the first few Google results for "ada hanya" (those that show these words in the snippets), all are actually "yang ada hanya" (the phrase is "yang ada", not "ada hanya").
I'm sure there are legitimate "ada hanya" phrases out there, but for this sentence, it should be "hanya ada".