I don't like it, sorry. I agree with PP that it sounds like yet another made up/trendy/wannabe cool sort of name.
All I can think of is the prison, sorry.
I know a little Ryker and he's adorable! I like it!
Ryker has some very familiar sounds. Makes me think of Ryan, Parker, Ryder, Walker, Rylan, Kyler, Laken, Brecken. I like the sound but I have trouble separating that from the prison. Ryker is very "Bad Boy" & it brings to mind tough names like Rogue, Vandal, Wilder, Cannon, Ransom, Beretta, Striker.
Have you considered Iker?
It's a prison. So, no.
Oh, no. The spelling seems very trendy, and there's the prison...