In order to make a hardway bet, you have to place the selected number of chips in the proposition section. As for 1-1 and 6-6, they do not fall under the hardways category as they yield crap numbers.
The following four combinations are called hardways: Hard 4 (2-2) Hard 6 (3-3), Hard 8 (4-4) Hard 10 (5-5). However, you can have a total of 4 if you roll 1-3 too, but and the latter combination is considered “easy”. While the other pairs can be achieved via at least two combinations, here you have only one way to accomplish a hardway combination. For example, your pair totals 4 and it is made of 2-2, such combinations are known as “hard” because it is difficult to roll two identical numbers.