Hello,
You need to submit a Residence Certificate for preceding seven years of the qualifying examination for candidates who have completed their graduation through private study without any institutionalized education. This means it should be issued in 2019. 
For more information, go through the link below-
https://www.tspgecet.co.in/ts-pgecet-counselling-required-documents/
Good Luck!

Dear Aspirant,

Your residential certificate will not be valid for TSPGECET 2019. Because your certificate was issued in 2018. 

So you have to make another Residential certificate.

Best of luck.

Hope for best.