Welcome to Using English
Hello. If you want to indicate the birth order of a person in a family, how do you ask?:?:
How about the order of a president. For example, President Obama
This question comes up at least a few times a year.
English does not have a way to ask this question if you are determined to hear "sixteenth" instead of "sixteen". We can't say "how manieth?"
Just say "What number president was Lincoln? What number president was Obama?" The answer will probably be "16th" or "44th" but you have not lost any information if the person says "He was number 16."
Apparently other cultures care a LOT more about whether someone is the second son, the third daughter, etc., than most English-speaking cultures, because we don't notice that there is no easy way to ask this.
Just say "Where do you come in your family? Are you the oldest?" And the person will fill you in on the details. "No, I'm the youngest, I have two older brothers and an older sister" or "I have an older brother and sister, and twin little sisters" or whatever.
Please note in the future that you should use a title for your thread that is about your subject. You could have called this "Birth order." Also please note the corrections I have made to your post. Capital letters are an important part of English.