If you cannot physically visit a restaurant to make a reservation, you can do so online. There are a variety of websites that will allow you not only to make your reservation, but also to review restaurants before making your pick.
http://www.bookyourtable.com/ is one of the options available to you. This site allows you to make free online reservations throughout India, as well as compare offers, buffet-style restaurants and romantic locations.
Finding the best food outlet in India
http://www.dineout.co.in/ also offers a comprehensive review and booking service, whereby diners can locate very specific types of restaurants throughout India. This site comes with the option to book a party venue.
One of the nicest things about making a booking through this sort of website is that it sometimes comes with special offers. If you book through BYT now, for example, you could get a free glass of wine from a participating restaurant.