Hi Sachin, you can try to get through to Army field in the medicinal office field having biology. But it is not possible to get through to Navy and Airforce without Maths. But if you are a student having Physics, Chemistry, Maths, Biology in 12th and passing them with 60% in 12th, then you can even try for Navy and Air Force. 

Hello Sachin ojha..........

As you are a biology student you cannot give NDA exam ,though biology students can give the written examination,but the will not be allowed to give SSB interview with out 12th certificate which is  through PCM stream or PCMB stream.

DO note biology students will still have to give the 300 marks maths exam as well,if you took PCMB as your subject then you can give the NDA exam.

All the best 

Thank you