1.)First register urself on IT site (if u r not already registered) i.e. on incometaxindiaefiling.gov.in
2.) Download ITR form applicable to you (in excel utility)
3.) fill up the form
4.) validate each sheet of the form
5.) click on tax calculation
6.) then generate xml file.
7.) upload the xml file on IT site (mentioned above)
8.) take the print of the acknowledgement, sign the same and send it to IT dept. banglore (on address mentioned in the acknowledgement) through either normal post or speed post.