Rye breads are made with a mixture of rye flour and wheat flour because rye flour by itself does not possess the chemical properties necessary to produce a leavened product

One cup of rye flour is one cup.

Rye flour in Tamil is known as ராய் மாவு (raai maavu).

Dark Rye is normally a 100% wholemeal Rye flour, ie: with nothing taken out, so if you want the maximum health and nutritional benefits from your bread then this is the best choice.

Light Rye is a rye flour which has had some of the wheatgerm removed. It makes a lighter coloured, less dense loaf, and can be used in combination with Dark Rye to tailor a loaf to your tastes. A light Rye flour does not have to be bleached and some of the wheatgerm is left in, so it's not nearly as devoid of nutritional value as a standard bleached white flour would be.

If you actually meant "whole wheat" bread, then no. Rye is a different type of grain than wheat.

If you meant "whole grain" bread, then the answer is "not necessarily." Check the label for the ingredients. Some rye breads contain white flour, for example, which is not a whole grain flour.