Polydactyly simply breaks up to form the words “many fingers” and is congenital physical mutilation in humans and animals which results in extra growth of fingers or toes. Generally, such a case of extra growth of finger does not have any negative implications or any kind of hindrances in doing the daily work. But, in the case of armed forces, it is taken very seriously and such cases are given downright permanent rejection. This means that if you will go to the SSB medicals with extra fingers or toes then  you will be rejected on the grounds of polydactyly. 

The reasons are

The reasons are that the military clothing and equipment, including that of the standard gear such as gloves and footwear, comes in prescribed standard sizes. It would be too expensive and will often stand out for the makers to make items for people with extra fingers and toes. Sometimes, in an operational area, you are out of your gear or you lose it somewhere and no spare is in sight then it would be difficult for a soldier to arrange for proper gear.  Military medicals are often pre-determined according to the operational norms which are suitable for people with a certain type of physique. That is why you will not find any candidate with less height, other than that of hilly terrains or with other medical issues which can not be cured.