Index Attribute:

Entity Framework 6 provides Index attribute to create Index on a particular column in the database as shown below:

class Student
{
    public Student()
    {
    }

    public int Student_ID { get; set; }
    public string StudentName { get; set; }

    [Index]
    public int RegistrationNumber { get; set; }
}

By default, Index name will be IX_{property name}. However, you can also change the Index name.

You can also make it a Clustered index by specifying IsClustered = true and a unique index by specifying IsUnique=true.

[Index( "INDEX_REGNUM", IsClustered=true, IsUnique=true )]
public int RegistrationNumber { get; set; }

Download Code-First sample project for Index attribute demo.