Dear Das,
As Anupam has mentioned the order type for the REM activated materials would be PE.
Now in this case check if the BOM selection method has been maintained as 2 in the MRP4 view.
If I remember correctly only in these cases after MRP run, the system gives the order type as LA and
as you have mentioned after assigning the same in MF50 to the production version,then the order type
gets changed as PE.
Regards
Mangalraj.S