It does not have to be 6 holding patterns. It is 6HITS
6 approaches, holding, intercepting and tracking radials.
Fly an approach, go missed, intercept a radial and track it to a hold. Do 5 more approaches and you are done.
I wont go into the whole deal that it is the bare minimum and you should do more than 1 hold and 6 approaches because you know that, this is just for currency and not profficiency.
and since we love our FAR's
61.57 Recent flight experience: Pilot in command.
c) Instrument experience. Except as provided in paragraph (e) of this section, no person may act as pilot in command under IFR or in weather conditions less than the minimums prescribed for VFR, unless within the preceding 6 calendar months, that person has:
For the purpose of obtaining instrument experience in an aircraft (other than a glider), performed and logged under actual or simulated instrument conditions, either in flight in the appropriate category of aircraft for the instrument privileges sought or in a flight simulator or flight training device that is representative of the aircraft category for the instrument privileges sought --
At least six instrument approaches;
Holding procedures; and
Intercepting and tracking courses through the use of navigation systems.