When I took written , I used CCIE Written simulation tool from Netmaster Class (www.netmasterclass.com)
but seems like they have discontinued the product.
On the flip side, INE released updated version of CCIE R&S Written bootcamp couple of months back.
But older version had Practice simulation. Chances are pretty high that if you buy current version, you get access to older version too. But still check with them before you buy.