To reach Ujjain from Omkareshwar, you have a few transportation options:

1. By Road: The most common and convenient way to travel between Omkareshwar and Ujjain is by road. You can either hire a taxi or use a private vehicle. The distance is around 140 kilometers, and the journey takes approximately 3 to 4 hours, depending on traffic and road conditions. There are well-maintained highways connecting the two cities.
2. By Bus: Another option is to take a bus from Omkareshwar to Ujjain. Several private and state-run buses operate on this route, offering both regular and deluxe services. You can inquire about bus timings and book tickets at the local bus station or through online booking portals.
3. By Train: While there isn't a direct train route between Omkareshwar and Ujjain, you can consider traveling by train to the nearest railway station and then taking a connecting train to Ujjain. The nearest major railway station to Omkareshwar is at Khandwa. From Khandwa, you can catch a train to Ujjain. Be sure to check train schedules and availability in advance.
4. By Air: Ujjain does not have its own airport. The nearest airport is Devi Ahilya Bai Holkar Airport in Indore, which is about 55 kilometers away from Ujjain. If you prefer air travel, you can fly to Indore and then continue your journey to Ujjain by road or train.

Regardless of the mode of transportation you choose, it's advisable to plan your journey in advance, especially if you're traveling during peak seasons, and to check for any updates or changes in schedules.