Anybody knows where I can get .rk domains? Looks like nowhere so far - any idea?
Unfortunately, .rk is not a TLD that is offered anywhere. You can view the list of domain extensions available here:
Applying for a .rk extension isn't a worthwhile endeavour either. It costs around 185,000 USD and is up for delegation with ICANN.
Where you planning on using it for domain hacking? Something like fo.rk or spa.rk? Currently the .r* domain extensions available are: .re .ro .rs .ru .rw
Maybe something will fit. Otherwise, if might be best to think of another name for your site.
Note: Creating your own TLD will take LOTS of money and the capacity to create and manage your own server.