I will be more specific this time...
Server where the database resides has machine name "oracle816" and that's the machine(server) where tnsnames.ora file has a problem. My machine is "sak" from which I can connect to this server without any problem.
I have copied tnsnames.ora file from machine(this part) on to the server(oracle816) where it does not work, but still it is not working. That's what confused me... What else should I lokk for where ?
That's why I specified locations of all tnsnames.ora file on that server(oracle816) where I copied this and still doesn't work. And wanted to know which one it is using.

thanks
Sonali