is it possible to do agricultural engineering without having maths as a subject in 12
Engineering is a field of science that is governed by mathematics and physics on a equal level. Without mathematics is would be very much difficult for a basic understanding of this subject. Hence for engineering mathematics plays an important role.
Same for Agricultural Engineering too , students must have passed in 10+2 from a recognised educational board with physics, Chemistry and mathematics as a compulsory subjects.
This rule is for majority of engineering subjects except for biotechnology.
So I am afraid to tell you are not eligible for agricultural engineering , however you can build you career by opting Biotechnology, genetics ,bioinfomatics as a subject.
Thank you and don't lose hope .