Yes you can go for bachelor of arts in studies after completing diploma which is equivalent to 12th class standard examination. There are various colleges and Universities in India which accept bachelor of Arts admissions to the students who have completed their diploma instead of 12th class. For more details click on below link about Bachelor of Arts.

https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.careers360.com/courses/b-a-bachelor-of-arts/amp&ved=2ahUKEwj04auLxd30AhXmsVYBHf14BTIQFnoECAQQAQ&usg=AOvVaw0tJsN7bZ4bZ1bfX3ASMxRc