I don't think you can get your certified copy of Sale Deed online in Bangalore. The process that I know of is that you will have to make an application in Form 22 in the relevant Sub-registrar's office and pay the Statutory fee of around Rs 200- 300 to retrieve it.
Please remember that the application has to be filed where the Sale Deed was originally registered. From your question I couldn't figure out whether it is HSR Layout or BTM Layout. But I do know, that HSR Layout at the moment does not have a Sub-Registrar's office.