HRA claim in ITR if not shown in Form 16

one of my client received Reduced HRA i.e 19% instead of 24% of basic during PY 18-19 and his employer did not shown HRA exemption in his form 16 said you can't claim HRA exemption in case of reduced HRA. Now my query is that can I claim HRA exemption or not and if not can I claim sec 80gg deduction?