Can you bring underground conductors through a meterbase and into a panel

Not sure if I am understanding your question. Every home in our neighborhood comes through the base, with a disconnect, and then to the panel. My home in the GA mountains is also wired the same.

Branch circuit conductors should not pass through a meter base.

If you are asking about feeding additional conductors through the meter base and into the main panel or cut-off switch the answer is no.

If you are talking about Service Entrance Conductors, then you would help us to help you by giving a better description of what you are trying to accomplish.