Ga. Code § 36-3-2
It shall be the duty of the judges of the probate courts of the counties whose dividing line is sought to be changed to lay before the grand juries of their respective counties, on the first day of the next term of the superior courts after the publication of the notice and the filing of the petition provided for in Code Section 36-3-1, the original petition, together with all maps, plats, and other papers that may have been filed therewith. If such grand juries, by a two-thirds' vote of their respective bodies, approve the change applied for, they shall so declare in their general presentments. This action of the grand juries shall be certified at once by the clerks of the superior courts to the county governing authority in the counties to be affected, who shall, within 30 days from the date of the certification, approve or disapprove the application and certify their action to the judges of the probate courts of their respective counties. When the judges of the probate courts have satisfactory evidence of the concurrent approval of the grand juries and of the county governing authority in the counties to be affected, they shall cause an official notice of concurrent approval and a description of the line approved to be published for at least 30 days in a public newspaper having general circulation in their respective counties.
OCGA § 36-3-2