The term Aggregate Turnover has been defined u/s 2(6) of the CGST Act 2017 :
"Aggregate Turnover means the aggregate value of all taxable supply ( excluding the value of inward supply on which tax is payable by a person in reverse charge basis ) exempt supply, export of goods or services or both and Inter State Supply of persons having the *"same Permanent Account Number"* to be computed on all India basis but excludes CGST, SGST, UTGST, IGST and Cess.
Therefore, turnover of same PAN entities to be computed to get the value of Aggregate Turnover.