It is not clear from your question as to offences under what sections have been registered against the person concerned.
Firstly, law is the same even if the accused person is also a policeman. Secondly, what actually happened may perhaps be less relevant than what sections have been applied in the FIR registered or the charge-sheet filed for the offence that occurred.
In so far as driving by a drunken person is concerned, it is punishable under Section 185 of the Motor Vehicles Act, 1988. Such person shall be punishable for the first offence with imprisonment up to 6 months, or with fine which may extend to Rs. 2000, or with both. Therefore, for this offence, the person can be punished by merely imposing fine, but it all depends on the judicial discretion of the court.
Now, if such person had merely engaged in verbal arguments with the police personnel when caught while driving as a drunken person, then that may not amount to any serious offence. But, sometimes, in such cases, the police may even slap a charge under Section 353 of IPC. But, even this offence is punishable with imprisonment up to two years, or with fine, or with both. So, here also, the punishment of only fine may be imposed if the court deems it fit.
Dr. Ashok Dhamija is a New Delhi based Supreme Court Advocate and author of law books. Read more about him by clicking here. List of his Forum Replies. List of his other articles. List of his Quora Answers. List of his YouTube Videos.