The assuming of office by the retired judge of the Madras High Court would be followed by a notification calling for information on the agenda of the one-man inquiry commission.
To a question, Arumughaswamy said the probe would be transparent.
The state government had on September 25 announced setting up of the inquiry commission headed by the retired high court judge.
Justice Arumughaswamy would hold the inquiry into the circumstances leading to the hospitalisation and death of Jayalalithaa on December 5 last year after 75 days of treatment at the Apollo Hospitals here.
The commission shall submit its report in three months, as per the Government Order.
According to the GO issued last month, the Commission's terms of reference would be "to inquire into the circumstances and situation leading to the hospitalisation" of Jayalalithaa on September 22, 2016 and "subsequent treatment provided till her unfortunate demise" on December 5 the same year.
The probe was a key demand of the then rebel AIADMK faction led by O Panneerselvam as a pre-condition for the merger of his camp with that of Chief Minister K Palanisamy.
The two factions had merged on August 21 with Panneerselvam becoming the deputy chief minister.