You can configure the Tenor to send all the incoming PSTN calls to your VoIP IVR, but once the calls are sent there, then the Tenor cannot redirect the calls. It would be the responsibility of the IVR to do reroute the calls to the endpoint.
If your IVR is radius based, however, you could configure the tenor to answer the incoming calls and interact with your Radius to do prepaid or postpaid services. Once the call is authenticated then the tenor will route the call based on its configuration, to an endpoint.
If you need further help or clarification, you may contact me at firstname.lastname@example.org