You will not have trouble finding alcohol in India. All cities and towns, (except for the dry states - scroll down) and most villages in India are equipped with alcohol stores. You should look for English Wine shops. These shops sell all sorts of imported and domestic liquor. If you mistakenly end up at a local wine shop, you will usually only find cheap, home brews (not advisable).
Most places, wine shops close between 8 pm and 10 pm. Also, check for dry days. During certain religious festivals, wine shops remain closed.
Liquor is served at most restaurants in tourist places, pubs and bars scattered around all cities.
Cost of liquor in India
Booze regulation laws in India fall under the state authorities. Which is why, prices of alcohol vary from state to state, cheapest being Goa, Pondicherry, and Daman and Div, and costliest being Mumbai.
Certain states in India are known as dry states, like Gujarat in the west and Nagaland and Mizoram in the North East, where alcohol is not available. It is illegal to carry alcohol from other states into the dry states.
In the South of the country (Kerala & Tamil Nadu), alcohol is available only in 5 star hotels and their restaurants. These states will ban alcohol altogether in the coming years.