import java.util.*;
import java.lang.*;
import java.io.*;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
 
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		String[] strings = { 
			"71346 G249 USD 70045620 27/08/2020 001 / 004",
            "71346 G249 USD 70045620/2020 27/08/2020 001 / 004"
		};
		String regex = "^.*?\\b([0-9]{6,}(?:/[0-9]{4})?)\\b.*$";
 
		for (String s : strings) {
			System.out.println(s.replaceFirst(regex, "$1"));
		}
	}
}

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