Dependency injection is correctly used in below code or not ?

// Registration Model

public class RegistrationModel
{
  // Properties
}

//Interface

Public interface IRegistration
{
 string Insert(RegistrationModel _objReg);
}

// BL

public class RegistrationBL
    {
        IRegistration _iReg;
        public RegistrationBL(IRegistration _iRegistration)
        {
            this._iReg =_iRegistration;
        }

        public string Insert(RegistrationModel _objModel)
        {
            return _iReg.Insert(_objModel);
        }
}


  //DL

public class RegistrationConcrete : IRegistration
    {
       public string Insert(RegistrationModel _objReg)
      {
             // Insert statement Here
      }
} 

// My code in controller For DI

  public class RegistrationController : Controller
    {
       
        RegistrationBL _objRegBL;
        public RegistrationController()
        {
             
            _objRegBL= new RegistrationBL(new RegistrationConcrete());
        }
  }