How to extract date from string?

In addition to Maciejs good answer here is another one.
This will work for dates from 1900 to 2899...

using System;
using System.Collections.Generic;
using System.Text.RegularExpressions;

namespace JBMG
{
    class Program
    {
        private const string PatternJmbg = "(?<DAY>[\\d]{2})(?<MONTH>[\\d]{2})(?<YEAR>[\\d]{3})\\d{6}";

        static void Main()
        {
            var jmbgList = new List<string>
            {
                "0101006500006",
                "1311970000000"
            };

            foreach (var jmbg in jmbgList)
            {
                var match = Regex.Match(jmbg, PatternJmbg);

                if (match.Success)
                {
                    var dayString = match.Groups["DAY"].Value;
                    var monthString = match.Groups["MONTH"].Value;
                    var yearString = GetCompleteYear(match.Groups["YEAR"].Value);

                    var day = int.Parse(dayString);
                    var month = int.Parse(monthString);
                    var year = int.Parse(yearString);

                    var dateTime = GetDateTime(day, month, year);

                    // Now you have a DateTime object...
                }
            }

            Console.ReadKey();
        }

        private static DateTime GetDateTime(int day, int month, int year)
        {
            return new DateTime(year, month, day);
        }

        private static string GetCompleteYear(string partialYear)
        {
            if(string.IsNullOrWhiteSpace(partialYear)) throw new Exception("Input string must not be empty.");
            if(partialYear.Length != 3) throw new Exception("The length of the input string must be 3.");

            return partialYear[0] == '9' ? $"1{partialYear}" : $"2{partialYear}";
        }
    }
}

private static int GetCompleteYear(int partialYear)
{
    if (partialYear > 999) throw new ArgumentOutOfRangeException();
    return partialYear + (partialYear >= 900 ? 1000 : 2000);
}
...
var yearString = match.Groups["YEAR"].Value;
int year = GetCompleteYear(int.Parse(yearString));

private const string PatternJmbg = @"^(?<DAY>([012]\d)|(3[01]))(?<MONTH>(0\d)|(1[012]))(?<YEAR>[\d]{3})\d{6}$";

I have found this:

if (unos.Substring(4,1)=="9")
            {
               unos= unos.Insert(4, "1");

            }
            else if (unos.Substring(4,1)=="0")
            {
              unos=  unos.Insert(4, "2");
            }

Is there any other way?

Quote:

How to extract date from string?

As you can see converting date string with missing information do not regenerate that missing information, it is because the date format is not standard.
You need to standardize the string to a standard date format, you need to reinsert the missing thousand of the year, and for this, you need to use your knowledge that it is a birthday of human.
To standardize the string, you need to extract the century and deduce what is the missing thousand digit.

Quote:

Is there any other way?

No, there is no other way.
Details may differ, on how you want to use language features, but it is the idea.

Thank you all for you solutions. I used solution posted by

Maciej Los

in combination with my solution, but i decided to create sql function and use it in computed column which hold date of birth extracted from JMBG.