Hi Aspirant,

Even if you have biology it is mandatory to have physics and chemistry in class 12 board levels in order to be eligible to give NDA.You need to give NDA examination alongside in various subjects which includes maths,Physics,History,Geography etc.NDA exam is conducted in two stages: written exam and SSB Interview. The written exam is conducted in two shifts- morning and afternoon. The written exam is divided into two parts: Mathematics and General Ability Test (GAT)

Hope it helps!!!