Ankara is capital of Turkey, and it is close to Eskişehir.

There is high speed train between Ankara and Eskişehir multiple times per day.

You can use Ankara Air shuttle bus to reach Ankara Train station you need to get off at Eski Gar Station as  train station is not last stop of this shuttles.

Other choice is public transport you can use EGO-442 bus to reach Ankara gar.

High speed and regular trains depart from different building both buildings are next to each other.

Check Train page for more information.

If you would like to come Eskişehir with bus, you need to arrive Ankara Intercity Bus Station (Aşti)

You can take airport shuttle, check timetable at  Havas web site.

Other option is public transport, take EGO-442 bus.

Check bus page for more information.

You can also use taxi to reach both train station and bus station.