The information bulletin states that Candidates need to furnish the income details of Father/Mother/Guardian. But ideally the certificate that you upload should have your name as S/o or D/o of your either your Father/Mother/Guardians name. But because you do not have any source of income, even uploading your Mother's income certificate will be fine because you did mention your mother's details in the Personal details column. So this will not pose any problem. Neverthless, please mail NTA and confirm with them. You can write to them at: neet @nta.ac.in