Yes you can- but should you?
I suggest that you respect the others who are paying to enjoy a mature rated movie and get a sitter. I know you say your child will behave or sleep but you cannot guarantee that a loud noise will not wake him and scare him.
Before you all think I am anti-kids let me clarify that I have 4 of my own. Just because I have kids does not mean that I have the right to take them with me when they might disturb others who are trying to enjoy an evening out just because I will miss them.
Now if it is a kids movie that is entirely different. Those who attend expect kids to be there. But this is an R movie- intended for mature people.
Just my opinion.