For < RM120K, I would suggest you get a 2001-2002 325. But as with any 2nd hand car, you would have to search high and low to find one that suits your requirements, whichever they may be.
In general, key things to look out for are: mileage, overall condition of car, service records, undercarriage, etc.. Specific things you might look out for are mods, reverse sensor, rims, angel eyes,etc...
Find one that suits your liking, test drive it then if you are really convinced that is the car for you, take it to a well established bimmer mechanic to have it looked at before you buy.
Good luck man!