India postal code validation not working mvc 5

Question

Hello all,

 

I'm working on MVC 5 project, there I have add postal validation  like this,

 

[RegularExpression(@"^\d{5}(-\d{4})?$", ErrorMessage = "Please Enter Valid Postal Code.")]
       public string Pincode { get; set; }

 But the problem is, 695028 ; that is 6 digit not working.

 

Please help me...