how very senior citizens can file their income tax return without physically going to the IT office ?

there are a very large no of income tax payers who prepare their returns all by themselves .The amount of tax is small or it may be even nil in some cases.If it is sent by registered post, the acknowledgement form is not received back.
If it is submitted electronically, there is the question of digital signature,( to subscribe to a digital signature is a costly proposition). In these days of electronics how it can be done in a proper way ?

The answer is to be on the Indian context

Can i apply for local tax registration like VAT renting a Virtual office in Karnataka?

We would like to know few things about applying for VAT/ TIN registration in Karnataka.
1. Can i apply for vat/ tin number renting a virtual office?
2. If yes which will the cheapest way to get virtual office?
3. If virtual office cannot be used for the purpose of tax registration, then where can i find cheapest office space for rent in Bangalore or Manglore. My budget would be not more than 4000/- and we would hardly be using the space.

How to change my address in Income tax office?

I hv applied for PAN card from delhi, and i hv got my PAN card 10 months before. but my adress is incorrect in Income tax office. Now i hv to apply for my TDS return and my adress is wrong. so can anybody tell me how can i make my address correct in Income tax data? and how much time it will take? plsssss help me out