The Classic Cache Redirection policy is deprecated from NetScaler 12.0 onwards and as an alternative, Citrix recommends you to use the Advanced Cache redirection policies. You can also use the nspepi utility tool for the conversion.
A cache redirection virtual server applies cache redirection policies to each incoming request. By default, if a request matches one of the configured policies, it is considered non-cacheable, and the NetScaler appliance sends it to the origin server. Other requests are sent to a cache server. This behavior can be reversed, so that requests that match configured cache redirection policies are sent to cache servers.
The NetScaler provides a set of policies for cache redirection. If these built-in policies are not adequate for your deployment, you can configure user-defined cache redirection policies.