This achievement is for uncovering Goto's true identity. (I think--it might be 13)
SPOILERS!!!
Name and description: You ARE the droid I'm looking for: Deduce G0-T0's identity
In order to discuss this with Goto, you must have a high influence with Goto and have had some specific interactions. GoTp appreciates ruthlessly protecting the Republic. Not the people, but the infrastructure. It is very easy to displease him, so save before and after each conversation.
You also must have done some number of the following.
In the Hutt's Pazzak Den, talk to (and maybe fix) a droid that always loses at Pazzak.
At the Docks on the Hutt planet, in the apartments, talk to a bith (butthead). He needs help tracing a signal. When you return, he will be dead. Pick up his datapad.
While playing as T3-M4 in the Hutt's lair, Talk to all the droids there.
Encounter (and maybe defeat) a swope racing droid near the Ebon Hawk.
There might be others.
Goto is the original Droid sent to Telos.