Yes you can mix different flour to get goodness of all. There us no fixed promotion to be followed. You can use 50% of either oats/ragi/besan/moong/jawar/barely flour and 50% wheat flour for best results. Keep rotation your options every week. Only changing flour can't assure your complete management of stone and cholesterol. Alter your through out the days diet to get considerable result. www.allaboutdiets.in

U can use multi grain. But changing only flour won't help u need specific diet also as cholesterol levels need to be controlled and for kidney stone u need some foods to be avoided

You can use barley atta mixed with normal atta in lunch n dinner and proportion should be1:3. This can be used for one week. Another week add oat bran in normal atta in a proportion of 1: 4. This will give you expecting results