Sana,

What is traceobject in
"$mobilenode log-target target-object" command?
And how can I create it?

Here is a link to the general ns2 documentation that explains common commands: http://www.isi.edu/nsnam/ns/doc/node195.html. This, alongside other provided examples within the documentation would be a good place to start to give you incite on logging.

Is it ok to use TCP agents for UWSN?
I am trying to make use of them, but when I do so , it shows zero energy consumed.
Not showing energy consumption at all.

While Agent/UWSink and Agent/UW_VBVA_Sink have been tested/used in the past I am unaware of the differences between these and TCP agents. Presumably you should be able to use other agents but you may be lacking certain specialized underwater characteristics (accompanied by potential negative outcomes).

I am using setdest to move my node.
After setting destination, I am sending packets to the node at that location, but it's not receiving.
The receiver and sender nodes are adjacent to each other , still its not receiving.
I am using VBF and broadcast MAC.
Does anybody know why?

In the past I recall there being a bug with packet timing of the receiver due to node mobility (which I am not sure was patched), but the receiver should be getting the packet assuming all other components of the transmission are not suppressing this communication (range, txPower, recv state, etc.). Or potentially protocol related delivery restrictions such as the receiver is dropping the packet due to low desirableness factor.

I am studying VBF, in which there is a Sink initiated query concept in which we can have location dependent query;

To serve this purpose, if I'm nt wrong, we are provided with "announce" command that calls bcast_interest method.

Now, when I call announce , no node receives the packet, Why is that so?

My best guess without looking at any code is that the header fields are not set properly. From UWSinkAgent::bcast_interest() printf do you notice any questionable components?

-Robert