Dear aspirant,

The annual income/status of the parents of the applicant should be based on financial year ending March 31, 2019 as per official neet broschure,if not or it has parents income status as per previous year then you can renew it You can renew the certificate by applying for it at the district office of one's own city or district.

Also you can refer to the detailed guidlines and format for the certificate from oficial broschure here https://ntaneet.nic.in/Ntaneet/ShowPdf.aspx?Type=50C9E8D5FC98727B4BBC93CF5D64A68DB647F04F&ID=1B6453892473A467D07372D45EB05ABC2031647A

Hope this helps