If it goes to CGK - Someone asked for outsized cargo. Last time I saw it at CGK was for a Russian Trade Show in Jakarta, they piled all the stuff into the AN124.
I like seeing the AN124 at CGK because they parked it at Ramp 1A, which is opposite 1A(R) (Cargo), in open view of everyone entering the terminal complex !
If it goes to HLM (Halim Airport), and parks at the civil ramp, it's for an aid shipment for disasters.
If it goes to HLM and parks at the airbase, (it did that a few years ago), it was carrying several tonnes of AK74 rifles ordered for the police. (Night arrivals and departures)