Ok am still waiting for update from Data base team in the mean time i tried to re-configure the SIA node to point to another data base server and start the CMC the user was able to log in to CMC.
I still have to check if the TNS error is the main cause for the error. Once i receive update from database team i will update the TNS ora file and retry again to see if that fix the issue first.
thanks
karthick