Which itr form fill?

I am working in Pvt company as a contract basis. I have received monthly Gross salary Rs. 10,000/- with 10% deduct the tds after net received Rs. 9,000/- pm. & I have also some part time work on commission basis. Monthly commission received Rs. 4,500/-after deduct the 10% tds. In both cases company issued Form 16A. Which ITR form applicable to filled against above income? Can I fill previous 3 yrs return in this year & what is due dates.... Plz suggest me, Thanks in advance....