Many online businesses can be managed from anywhere,  but you may need a virtual office if you have to meet your offline customers.

Some of the companies offering virtual offices in India are:

Apexone http://www.apexone.in
Regus  http://www.regus.co.in
Servcorp  http://www.servcorp.co.in
Virtuindia – http://www.virtuindia.com
Splendor Virtual Office – http://splendorvirtualoffice.com

Facilities available include mail collection and forwarding,  telephone calls,  use of office space for meetings. Prices vary depending on the facilities needed and location of the virtual office, starting from Rs 1000 per month .  The offices are available in major metro cities like Mumbai, New Delhi, Chennai, Bangalore, Hyderabad.