Intimation u/s 143(1) received with wrong calculation

Hi,

I recently received Intimation U/S 143(1) from Income tax department for AY 2013-14. The intimation shows that I need to pay some money as the tax paid by TDS was less than it should be. I noticed that the calculations don't show an HRA deduction. The intimations shows a comparison of tax details which I filed to what the department has calculated. 

After considering HRA I wouldn't be required to pay any tax.

How do I communicate this to IT dept? I can't find Section 10 under reasons while filing a rectification request. Please help.

Thanks,