using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

         List<obj> lsobjdata = new List<obj>

{

        new obj { Name = "xyz", PropertyName = "Volume", Id= 1, Value = 25 },

        new obj { Name = "abc", PropertyName = "Volume", Id= 1, Value = 23 },

        new obj  {Name = "abc", PropertyName = "Oil", Id =1, Value = 45},

        new obj { Name = "xyz", PropertyName = "Volume", Id= 2, Value = 25 },

        new obj { Name = "abc", PropertyName = "Volume", Id= 2, Value = 23 },

};

​

​

            var results = lsobjdata.GroupBy(x => new { x.Id, x.PropertyName })

                                   .Select(x => x.OrderByDescending(z => z.Name).FirstOrDefault());

​

​

            foreach (var item in results)

            {

                Console.WriteLine("Id : {0}",item.Id);

                Console.WriteLine("Name : {0}",item.Name);

                Console.WriteLine("PropertyName : {0}",item.PropertyName);

            }  

    }

}

​

public class obj

    {

        public string PropertyName;

        public string Name;

        public int Id;

        public int Value;

    }