Form 15 G is for normal citizen to save TDS


I am home maker and retired bank officer at age 36. I want to invest my money in post office or other investment.If i submit form 15 G will they deduct TDS on my interest income?
It is very confusing…some people say yes some say no . I have no other income source other than interest. Now income tax limit is 500000 and my income is not more than this yearly.
Please advice.