If you were not a resident of Georgia in 2021 you will need proof from your employer that the income reported on your 2021 tax return for Georgia Income and Georgia taxes withheld was incorrect on the W-2. The employer would need to provide a corrected W-2 for the Georgia income and taxes withheld.
Just amending the Georgia state tax return without any type of proof that severance income was included on the W-2 will be rejected.
