Have at least one bottle of each of the following spirits. Sure, if you like your scotch, keep six bottles, but don't get caught out by not having any of the following. Which brands you keep are up to you, but try and aim for the median. With white wines, Chardonnays tend to suit the Indian palate well and for Reds keep a Cabernet-Sauvignon or a Shiraz at home.
Foreign brands are available, but if you entertain people, even once a month, always keep a case of beer at home (with a couple of bottles in the fridge at any given point) and local brands work quite well.
A good selection of liqueurs can not only help you make cocktails, but also give a choice for a nice after-dinner drink. Always have a citrus liqueur, because those are very versatile tools. Try and use the following list as a guide.
Unless you have a 24-hour convenience store near your place, keep a few mixers in your house always. Soda and tonic water are essentials as is a cola and at least two different types of juices.
Even if you are not the type to mix up drinks, if you ever want to play around with the tools of the trade, have the following things at home. None of these cost too much, but you should buy a decent one.
Ice goes without saying, but the following tools are also essential for a "good" home bar.