Complex sentence: Though these policies were partly successful, after the 1989 Velvet revolution, Roma are once again on the fringe of the society, with generous social system on one hand but a system that fails to effectively integrate them into the mainstream society.
Split into simpler sentences: Though these policies were partly successful, after the 1989 Velvet Revolution, the Roma have once again found themselves on the margins of the society. On the one hand, there is a generous social system, but the system fails to effectively integrate them into the mainstream society.