You can pick this assignment up during the core mission in Feros. When you reach the Skyway Weigh Station you’ll have a conversation with Ethan Jeong and Juliana Baynham, after which you can talk to Gavin Hossle, who will ask you to recover some data from his console in the ExoGeni headquarters building.
This assignment runs largely in parallel with the core mission on Feros, which also takes you to the ExoGeni headquarters. Once there you’ll have to fight through a Krogan Commander and a Geth Shrine to reach a room with three passages (including the one you entered from) and a barrier blocking the northern exit. Go down the northeastern passage and defeat three Krogan, then search “Gavin Hossle’s Console” to get the data he wants.
Continue with the core mission and when you dislodge a geth ship you’ll be able to exit ExoGeni headquarters. Return to the Skyway Weigh Station and, after some drama with Ethan Jeong and Juliana Baynham, talk to Gavin Hossle and give him his data to complete this assignment.