How to file return for ay 10-11 now? please help me

Hi, I’m not sure if this can be answered. I’m unable to find my return for AY 10-11. (Either in the tax department website, my old mails, etc). I have filled for AY 09-10, 11-12, 12-13 (I have those proof with me), but not sure whether I filled for AY-10-11 or not. Yesterday I have received one letter from income tax department as below —————————————- Sir/Madam, Subject: Non filing of income tax return –Reg 1.The Income tax department has received information or financial transaction/activities relating to you. A list of some of the information for financial year 2009-10 onwards is provided overleaf. As per records, you do not appear to have filled income tax return for Assessment year(s) 2010-11. 2. You are requested to furnish your response in the enclosed proforma to the undersigned by post within 10 days. Please note that your personal presence or presence of any authorized representative is not required. 3. if no reply is received, within specified time, it will be inferred that you have not filed income tax return for the relevant assessment years and proceedings under income tax act, 1961 may be initiated. Yours Faithfully, (Income tax officer) ———————————————- I am panic now. Do not know what to do. I am sharing details of my income for FY 09-10 (AY 10-11) below. Please provide your honest opinion. Please just not say “Contact some CA” (Anyway I will contact CA). But before that I need your opinion. I am salaried Software engineer. I was worked for 2 different companies that financial year. I have 2 form16 for that year. When I calculate both form16, I found below details, Total “chargeable under head salary” = 1509862 Total Tax deducted by two companies = 223340 Note: I had house building loan that time. Under 24(D), they considered 1.5L deduction and under 80(c) they consider 1L deduction. Also to mention this house, I had rented for monthly 3k = 36000 Rs/ year (which were not included in this above calculation). So can you please tell me how to file this return? And do I need to pay extra tax with penalty? And how much do I need to pay (including tax +penalty) if any? Please help me. I am little bit tense, after seeing this letter from income tax.