Can I Get a Breast Augmentation at 16 Years a Old ?

Unfortunately, unless you have a congential/developmental deformity, you need to wait until the age of 18.  If you are considering silicone gel implants, then you will need to wait till you are 22.  As others have stated, your breast may still undergo changes and growth even into your 20's. 
 

breast surgery can be done for developemental problems

these include severe unevenness,  tubular deformity

it is generally best to wait until at least 18 otherwise.

hormones change, growth can happen late even up to early 20's