Drinking alcohol is not traditionally part of the Indian culture, due to this you will find the legal age for drinking quite high. In most parts of India the age requirement is 21 with Delhi reaching 25. However Goa, India’s party state has a lower age requirement of 18 - you'll normally find that most venues aren’t that strict on reinforcing these limits.
The states of Gujarat, Manipur, Mizoram and Nagaland are known as ‘dry states’. This simply means alcohol here is illegal without a licence. When travelling around India please try to be respectful of these laws and the local’s beliefs.
Please be careful of homemade brews on sale in India - you never know what's in there.