import java.util.*;
import java.util.regex.*;
import java.lang.*;
import java.io.*;

class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		String[] arrays = {
                "registrationNumber:\"\"074-р\"\"",
                "registrationNumber:\"074\"-р\"",
                "registrationNumber:\"\"07\"4-р\"\"",
        };
        Pattern pattern  = Pattern.compile("(.+:)\"(.+)\"");
        for (String string : arrays) {
            Matcher matcher = pattern.matcher(string);
            if (matcher.find()) {
                String result = matcher.group(2).replace("\"", "\\\"");
                String newString = matcher.group(1) + "\"" + result + "\"";
                System.out.println("NewString: " + newString);

            } else {
                System.out.println("Не найден: " + string);
            }
        }
	}
}