Can i do M.A after 12th?

No, you can’t pursue M.A after your 12th. It’s not possible since a Master of Arts is a post-graduate degree. The prerequisite for doing an MA degree is a Bachelor of Arts or other undergraduate degrees. Without a graduation degree, you won’t be eligible for an MA. 

After completing your graduation, you can apply for an M.A in Andhra University. Apart from the prerequisite, you also need to qualify for the entrance test conducted by the university to get admission.