SASSA Declined Reason IRP5 Registered status means you are IRP5 registered.
The SARS databases are picking you up as someone who pays tax which therefore means you are receiving an income.
SASSA Declined Reason IRP5 Registered ca be appealed if you are genuinely not receiving an income. To appeal for SASSA Declined Reason IRP5 Registered you need to log on to srd.sassa.gov.za and submit your appeal through an appeals form.