If not factory equipped from new Rollei originally offered two different 220 modifications:
1) A switch by the strap lug.
To use 220 film you expose the first 12 then push the switch foreword. This returns the counter to zero. Then you advance to #1 the second time and expose the second 12.
2) A switch by the wind handle with the numbers 12/24 on it.To use 220 film, start with the number "24" on the top. After you expose the first 12 the advance will not work until you flip the switch so that the number "12" is on the top. Then you advance to #1 the second time and expose the second 12.
http://www.rolleirepairs.com/220mod.html
Early 2.8F's and 3.5F's pre-date 220 film 1965
In a Rolleiflex the film plane is governed by the guides that the pressure plate pushes the film 120 or 220 against, but that plate must have a strong enough spring mechanism.