dear Menon : defination of aggregate turnover as per section 2(6) cgst
"aggregate turnover" means the aggregate value of all taxable supplies [excluding the value of inward supplies on which tax is payable by a person on reverse charge basis], exempt supplies, exports of goods or services or both and inter-State supplies of persons having the same Permanent Account Number, to be computed on all India basis but excludes central tax, State tax, Union territory tax, integrated tax and cess