The correct sequence in ascending order of size for administrative divisions in medieval India is

1. Pargana
2. Sarkar
3. Suba

Pargana: The smallest unit was the Pargana, which typically comprised a group of villages. It was the most basic level of administration. Sarkar: A group of Parganas formed a Sarkar, which can be understood as a district or province. Suba: The largest administrative division was the Suba, which encompassed several Sarkars. It was equivalent to a modern-day state or province.