Can you turn this basement into an independent unit?

[Delsater Z.]

Hello! I hope I chose the correct category for this question.

Im considering to buy a Duplex near Decatur GA (Atlanta area) which happens to have a basement with its own separate entrance.

Is it /feasible to turn this Basement into a 3rd independent unit, legally speaking?

The house is built on a slope, allowing the basement to have windows on all 3 sides (only 1 side fully underground).

The seller's offer includes this Basement as a 3rd rentable unit.

However it is not currently registered as an independent unit and does not yet have water/electrical meters.

(this house was converted from single family to duplex about 12 years ago)

The owner has already done some work: frames for partition walls (each room has a window) as well as electrical wiring, plumbing, AC and ducting. I'd have to complete finishing it AND get water/electrical meters.

Does this deal sound legit? Is it feasible? Can I turn this basement into a 3rd rentable unit?

I'd really appreciate your insight, cheers!

Z