Hello,
Yes, it is mandatory to submit the residence certificate, as mentioned on the official website. To know the list of certificates you need to submit, go through the link below-
https://www.tspgecet.co.in/ts-pgecet-counselling-required-documents/
Good Luck!

Yes it is mandatory to show  your address  so that you can tell you belong  to Telangana state .

You can also show your other address proof like Aadhar card and electricity or water bill.

Also you must visit eseva or meeseva and apply for residence certificate

Show that application to authorities