"Making out" something means being able to see or hear it, even though it's difficult to see or hear. "Make out ___" is often used in the negative form:
I heard them talking about me, but I couldn't quite make out what they were saying.
I can't make out your handwriting. What does this say?
"Make out" is often followed by a clause that starts with "where", "how", "who", "what", "when", or "why":
Can you make out how many of them there are?
It was really dark out, but Ralph was able to make out what they were doing.
When you're using "it", "them", "one", or other short words like these as the object, "out" comes afterward:
I can't make it out.
Be careful. When you just use "make out" without any object, it means to kiss someone heavily!