Normally, people use this expression for things.
For example, "If you lose your job at least you have good skills to FALL BACK on.
"If this investment fails at least I have my savings to FALL BACK on".
It basically means the same as RELY ON.
However, if you are talking about people, it would be better to say,
"I have friends to COUNT ON when I need help".
"I can usually COUNT ON my mother to give me good advice".