To use Ctrl+R in SQL Server 2012 use below steps
1) Open SSMS.
2) Go to Tools -> Options.
3) In the left panel click on “Keyboard” for selecting it.
4) Once “Keyboard” is selected in top of the right panel press the “Reset” button.
5) Answer “yes” to the question dialog “Keyboard mappings will reset to their defaults. Continue ?”
6) Click OK in the Options dialog.
After following above steps you are able to use Ctrl+R and other SQL Server Short Cut methods which was working as per older version or expectation.