Hi Sanjay,
as described by the previous replies, the so called "route domains" may be an approach to meet your requirements.
Route domains allow to build independent routing facilities and prevent from cross communication between them i.e. for security reasons or in case you are using overlapping IP address space.
But perhaps the so called "AutoLastHop" feature already does what you are looking for?
AutoLastHop is a feature of the TMOS connection table. Whenever a new connection comes in it stores the inbound VLAN and nexthop MAC address (will be the one of your nexthop router or firewall on inbound VLAN). All received responses will be returned exactly through this path as long as you are not disabling AutoLastHop globally or for a particular virtual server.
This way TMOS makes sure traffic flows symmetrically and responses are delivered through the same path were the request was received from.
The feature does not help in case TMOS has to forward traffic to a non-locally attached network (i.e. with network virtual servers in IP forwarding mode). In this case VLAN specific virtual servers (PerformanceL4 mode, Destination Address/Port Translation disabled, Pool containing the next hop router interface IP with port "0") will do the job.
Back to your initial question: without using routing domains it is not possible, afaik.
Thanks, Stephan