Indiana Code Title 2. General Assembly § 2-5-1.1-3

Sec. 3. (a) The chairman shall fill any vacancy on the council in a position held by virtue of office.  The person appointed shall be from the same house and party as the person whose position was vacated.  In filling the vacancy, the chairman shall accept the recommendation of the ranking member on the council from the house and party affected.  The replacement shall serve until his successor has been selected.

(b) Any vacancy in a position held by appointment shall be filled by the council member making the original appointment.