Oil leakage from the engine, ABS Light showing and 4x4 Light is also showing
ABS light is on because the 4x4 light is on.
Is it in 4 wheel drive ?
BMW X3 is permanent 4x4 (awd), it uses the wheel speed sensors for abs and 4x4
That would almost surely indicate a need for either replacing a gasket, or–possibly–re-torqueing some bolts, but without knowing exactly where the engine’s oil leak is located, nobody could possibly give you a definitive answer.
In any event, unless you are a skilled diagnostician/mechanic, you need to take your vehicle to a qualified mechanic. I strongly suggest looking for an independent foreign car specialist in your area, as repairs at BMW dealerships are quite pricey.