Without having looked at the code you have created, it sounds like you are getting the ticket from a path including a virtual proxy and then requesting the resource from a different proxy (in this case central). Another potential issue is you are using the ticket after it has expired.
Lokesh, it is not possible to change the ticket expiry. But what you could do is get the ticket and create a request that accesses the sense server to another resource with the qlikticket so that you get a session, and then allow the user to pick the app they want and go to it through your interface.
Unrelated, why are you referencing port 4242 when using the qrs rest interface? It is not necessary.