Hi SUVENDU
YOU RIGHT ,BUT I think it depend on preferred algorithm by vendor, But the major issue is that the MS has ability to search first on the (last registered OR home registered) PLMN (MCC, MNC) & this is ( According to PLMN list stored on SIM), so it made some kind of priority to search first for HPLMN, no matter of where the PLMN detection stage on algorithm flowchart, if it not HPLMN it will rejected & searching cycle start again. & thus by some ranking after unavailability of HPLMN the MS trying to roam on the next ranked PLMN. (PLMNs with SS > -85 dBm in random order)according to the registered list on SIM.
But note that there is not cell selection & camping before (PLMN selection)
BR