The commission headed by retired judge A Arumughaswamy had asked Apollo to submit all the documents related to the treatment of Jayalalithaa, who passed away in December 2016.
This follows allegations that Ms Jayalalithaa's death was triggered by poor medical attention.
The panel has ordered deposed AIADMK leader V K Sasikala's advocate Raja Senthurapandian to appear before it on January 22.
Ms Sasikala had been a long-time confidante of the late AIADMK leader and lived at her residence here.
Meanwhile, rebel AIADMK leader T T V Dhinakaran and his supporters called on Ms Sasikala in prison in Bengaluru on Friday.