i got 60 percent overall but only 40 in biology can i get afmc?

No you cannot. Because AFMC criterias are different from neet. For AFMc, candidates must have passed 12th IN the first attempt with 50% scores in each of the 4 subjects (physics, chemistry, biology and English) and also the overall PCB aggregate should be 60% . So you don't satisfy this condition since you got 40 in biology. So sorry to say, but you cannot apply for AFMc.

Thank you