Hii!
You can a lot of diploma of diploma courses and certificate courses after you pass class 12th in Art's stream. Some of the courses, you can consider and select out of are -
Diploma in digital marketing
Diploma in 3D animation
Diploma in multimedia
Diploma in graphic designing
Diploma in computer applications, programming
Diploma in web designing
Diploma in digital film making
Etc.,
Hope this helps.
Good luck!