We have an external web url which will come on our frontend f5 VIP but server is responding to the external passing the F5, needs to route back to F5

As long as you have the routes on the pool members pointing to the F5, it should go through the F5. I am assuming that the default routes on the pool members are pointing to some other router. In this case, you can add SNAT pool or SNAT Automap to force response traffic to go through the F5.