Thanks all for your replies. I am little confused as I am new to F5. Currently, I have no IP routes as the self-IPs,Floating IPs, and the backend servers all reside in same VLAN. If I create any new self-Ips in new VLAn and new routes, would it cause any issue for the exisiting servers?
Without seeing your network the only answer i think we can give is "it depends" If for example you have a default route set somewhere. netstat -rn i think from cli will confirm this, don't worrk about the MGMT route, its the other ones that are important for traffic flow. Then if you add more specific routes to and from your internal servers then in theory you shouldn't affect your current flows. To try to help, this might be more of a networking question rather than a f5 one. If you have a network guy you can talk it through with it could really help you!
As said above, look up auto last hop as this can help a lot but also cause you a headache depending on your network.