I didn't see how you pass in whether it is 6 months or 12 months from the date.

That aside, when you're doing the conditional format, you can use the following formula: (I'll assume the date you are considering is in B2 as you used in your example and you want 6 months from now.)

=AND(DATE(YEAR(B2),MONTH(B2)+6,1)<=TODAY(),TODAY()<DATE(YEAR(B2),MONTH(B2)+7,1))

If you have the # of months in another cell (like C2):
=AND(DATE(YEAR(B2),MONTH(B2)+C2,1)<=TODAY(),TODAY()<DATE(YEAR(B2),MONTH(B2)+C2+1,1))

Basically, this is just saying that you want (1) The first day of the month 6 months from the date (B2) to be LESS THAN OR EQUAL to today's date, AND (2) Today's date to be LESS THAN the first day of the month 7 months from the date (B2).

For some reason, to me the formula makes more sense then my explanation of it, but hopefully one of them helps you.

Scott