what is the correct ration to use flax meal as replacement for oil.

In general i consider flax more of an egg substitute than an oil substitute. It behaves differently than oil and absorbs liquid, creating more of a mucilaginous substance. If you do add it to your batter/dough, you need to increase your liquid at a ratio of 3 Tbsp liquid for every Tbsp of flax meal. If your bread is chemically leavened, expect to get a more dense end product. If it contains enough savory ingredients and a good amount of salt, you could try substituting part of the oil with some unsweetened apple sauce instead, it behaves more like a fat in a batter.

According to the brand I buy...( I assuming they are all similar) Its 1 Tbsp margarine, butter or oil = 3 Tbsp flax.