Dear Student,
Download the required form from e-seva site under revenue department, OBC form. (site may differ in your region- may be an MRO site) link given below :-

https://www.google.co.in/url?sa=t&source=web&rct=j&url=http://ap.meeseva.gov.in/DeptPortal/Application%2520Forms%2520New/Revenue-pdf/OBC%2520Application.pdf&ved=2ahUKEwi8kc7yk4DbAhVGKo8KHZPyAh4QFjAAegQIBBAB&usg=AOvVaw01LiA7cUMLaV2gfwLnscKy

Eligibilty criteria- Income under 6 lakhs annually. For kids of govt employees go thr below question.

2. Fill the form and attach required documents. The form is very detailed and mother and father signatures are also required.

Affidavit, court stamp,all your educational record from ssc to degree. In case pursing PG make sure to submit sem memo or college ID card.State BC certificate, previous obc certificateaadhar card or ration cardprevious 3 years IT Returns

3. Submit in nearby e-seva center and wait for 1530 days.

4. Youll get a message when your request is processed and you can collect the certificate from the same e-seva center.

Hope this might help you.