In equal weights, six row has more husk than two row. More husk, better filteration, lessening chances of a stuck mash. But more tannin extraction at high pH and temps. The six row around here is modified. The only stuff that is partially modified that I know of and use are Weyermans Floor Malt and Budvar, when I can get it. Neither will convert adjuncts on their own. That's one reason six row is tossed in. Depending on the style of beer. The recipe may call for step mashing. Usually Lagers are step mashed. The step mash mimicks the decoction mash process used in brewing Pilsner, without boiling the grain. The temp/rest ranges are determined by what you want to brew. If your plate worked with two row, it will work with a mixture. If your gonna dump a few pounds of corn or rice in, pay special attention to sparging and run off rates. There's a lot of info on what you're asking, on this site. Seek, and ye shall find..Noonan's book on brewing lager has a lot of info on what you're asking.