Hi Kanishak,
You mentioned this was working before (ITIM 5.0) and migrate to ITIM6.0 make it not working.
First of all, do you have any documentation that mentioned how to integrate between ITIM and SM? If there is, I suggest to revisit the document. What I suspect is something get overwritten while perform the ITIM upgrade.
Based on what you explain, it seems SMSESSION was fine but the backend seems unable to consume the cookie and that's why you get application login page. I'm not sure if ITIM hosted on Websphere server. If it is, you might need have TAI on Websphere so it can consume the cookie and pass the principal to Websphere. The question is who in ITIM responsible to consume the SMSESSION cookie?
However, as I mentioned earlier, it was working fine in ITIM 5.0. If ITIM 5.0 has no TAI on the backend server, then I doubt ITIM 6.0 need it.
Regards,
Kar Meng