Hsn in new GSt Registration

Yes, you can change the HSN code after registration if you have used the wrong code. 
To do this, you will need to login to the GST portal and navigate to the relevant section where you can update your GST registration details. 
You will need to provide the correct HSN code for your products or services, as well as any other relevant information, and then submit the updated registration.

Thank you Mitali