namespace StudentSystem.Data.Migrations
{
    using System;
    using System.Data.Entity;
    using System.Data.Entity.Migrations;
    using System.Linq;

    public sealed class Configuration : DbMigrationsConfiguration<ApplicationDbContext>
    {
        public Configuration()
        {
            this.AutomaticMigrationsEnabled = true;
            this.AutomaticMigrationDataLossAllowed = true;
        }

        protected override void Seed(ApplicationDbContext context)
        {
            //  This method will be called after migrating to the latest version.

            //  You can use the DbSet<T>.AddOrUpdate() helper extension method 
            //  to avoid creating duplicate seed data. E.g.
            //
            //    context.People.AddOrUpdate(
            //      p => p.FullName,
            //      new Person { FullName = "Andrew Peters" },
            //      new Person { FullName = "Brice Lambson" },
            //      new Person { FullName = "Rowan Miller" }
            //    );
            //
        }
    }
}

namespace StudentSystem.Data.Migrations
{
    using System;
    using System.Data.Entity;
    using System.Data.Entity.Migrations;
    using System.Linq;
    using Microsoft.AspNet.Identity;
    using Microsoft.AspNet.Identity.EntityFramework;
    using StudentSystem.Models;

    public sealed class Configuration : DbMigrationsConfiguration<ApplicationDbContext>
    {
        public Configuration()
        {
            this.AutomaticMigrationsEnabled = true;
            this.AutomaticMigrationDataLossAllowed = true;
        }

        protected override void Seed(ApplicationDbContext context)
        {
            if (!context.Roles.Any())
            {
                const string adminUsername = "admin@admin.com";
                const string adminPass = "administrator";
                const string roleName = "Administrator";

                var roleStore = new RoleStore<IdentityRole>(context);
                var roleManager = new RoleManager<IdentityRole>(roleStore);
                var role = new IdentityRole { Name = roleName };
                roleManager.Create(role);

                var userStore = new UserStore<User>(context);
                var userManager = new UserManager<User>(userStore);
                var admin = new User { Email = adminUsername };
                userManager.Create(admin, adminPass);

                userManager.AddToRole(admin.Id, roleName);
            }
        }
    }
}

Add Admin user in Seed method
Add Admin user in Seed method
