2 gstn having same pan no

As per notification 29/2021, GSTR-9C is applicable only if the aggregate turnover exceeds Rs. 5 Cr in the respective financial year.

As per Section 2(6) of CGST Act, 2017 (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, in the above case as the aggregate turnover for 2 GSTIN is only upto 5 Cr GSTR-9C is not required to be filed.

If the turnover above 5cr example 5cr one thousand 

GSTR-9C has to be filed for 2 GSTIN's separately.