What if we forget to declare 80C in form 16?

Hi,

A user has forgotten to declare his 80C investments in Form 16. And Employer has calculated tax payable without 80C and deducted accordingly.

Now the user realised his mistake and wants to declare his 80C investments.

As TDS was done without taking his 80C deduction into account  (and tax payable was NIL), if he declares 80C now, he has refund to claim.

Can he claim refund in such cases?

Thanks!