Hello aspirant

If you are resident of Andhra pradesh  then you must have applied for registration number from Andhra pradesh before getting it from Tamil Nadu.

You must talk to concerned authorities both , Andhra pradesh and Tamil Nadu government  officials.

You will need domicile of Andhra pradesh and you will have to cancel your registration number from Tamil Nadu.

Domicile is given to residents of particular state .

Those candidates are considered as residents of the particular state who or one of the parents has been living in that state for more than ten years .

If one of your parents gave domicile of Andhra pradesh then you can apply for Andhra pradesh registration number on the basis of domicile .