Which of the following is not mandatory for a commercial vehicle in Assam ?

The correct answer is option 2. Key Points Vehicle Registration, Pollution Under Control (PUC), and Fitness Certificate are mandatory for all commercial vehicles in Assam, as per the rules under the Motor Vehicles Act. Night Driving Permit is not generally mandatory for all commercial vehicles. It may be required for certain vehicles based on their nature and route, but it is not universally applicable to all commercial vehicles.