Section 185 of the Motor Vehicle Act is the relevant provision for drunk and driving cases.
Driving by a drunken person or by a person under the influence of drugs.—Whoever, while driving, or attempting to drive, a motor vehicle,
has, in his blood, alcohol exceeding 30 mg. per 100 ml. of blood detected in a test by a breath analyser, or
is under this influence of a drug to such an extent as to be incapable of exercising proper control over the vehicle, shall be punishable for the first offence with imprisonment for a term which may extend to six months, or with fine which may extend to two thousand rupees, or with both; and for a second or subsequent offence, if committed within three years of the commission of the previous similar offence, with imprisonment for a term which may extend to two years, or with fine which may extend to three thousand rupees, or with both.
Explanation.—For the purposes of this section, the drug or drugs specified by the Central Government in this behalf, by notification in the Official Gazette, shall be deemed to render a person incapable of exercising proper control over a motor vehicle.