using System;

using Newtonsoft.Json;

​

public class Program

{

    class It

    {

        public DateTimeOffset LocalTs

        {

            get;

            set;

        }

    }

​

    public static void Main()

    {

        var values = "{'localTs':'2021-03-08T20:59:03+05:30'}";

        var dt = JsonConvert.DeserializeObject<It>(values).LocalTs;

        Console.WriteLine($"{dt:o}");

    }

}