Dear Sir,
The states turnover will only be clubbed when the person makes inter-state supplies and all same PAN persons making interstate supply will be clubbed. For instance, AP Office makes 10 lakh interstate supply and Telangana Office made 10 lakh interstate supply, then in such a situation, it will be clubbed. And the aggregate turnover will be 10+10 = 20
Another instance,
AP Office makes 10 lakh intrastate supply and Telangana Office makes 10 lakh intrastate supply. Then your AT will not 10 + 10 lakhs as it will be 10 for AP Office and 10 for Telangana Office, not clubbing because it's only intra state supply.
Clubbing of two states supply (person having the same PAN) is in the case of interstate supply
Section 22(1) - Every supplier shall be liable to be registered under this Act in the State or Union territory, other than special category States, from where he makes a taxable supply of goods or services or both, if his aggregate turnover in a financial year exceeds twenty lakh rupees:
―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;