You would complete the Form 511 tax form if you are a resident of Oklahoma and you would complete Form 511 NR tax form if you are a part-year resident or non resident.
A resident is someone whose permanent home is in the state of Oklahoma for the whole tax year.
A part year resident is someone whose permanent home is in the state of Oklahoma for less than the whole tax year.
A non resident is someone who does not have a permanent home in the state of Oklahoma at all.
For more information on Form 511:
https://www.ok.gov/tax/documents/511Pkt-16.pdf
For more information on Form 511NR: https://www.ok.gov/tax/documents/511NRPkt-16.pdf.
