Supply to SEZ

turnover in State" or "turnover in Union territory" 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] and exempt supplies made within a State or Union territory by a taxable person, exports of goods or services or both and inter-State supplies of goods or services or both made from the State or Union territory by the said taxable person but excludes central tax, State tax, Union territory tax, integrated tax and cess;

Supply to SEZ is treated as export, thus it is to be considered while calculating turnover

As per Section 16 IGST
supply to sez is treated as zero rate supply & zero rated supply includes export supply
And
As per section 2[6] "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;

Hence aggregate turnover includes export supply so supply sez is included