arrest drunken people

It depends upon the fact of the case - 

In some states like Bihar, Gujarat, Lakshadweep, Mizoram, Nagaland it is illegal to consume any form of alcohol. In some states the age limit is set at 18, 21 or 25. If one is drinking within his premises without causing any trouble for people around him/her police cannot arrest him/her on the ground that he/she was drinking. 

Conditions - 

• The person has the legal capacity to drink 
• the substance he is consuming must be legal
• He/she is not causing any trouble to others 
• He/she is within their premises