Let R be a commutative ring with unity of characteristic r≥ 0 and G be a locally finite GROUP. For each x and y in the GROUP ring RG define [x, y]=xy-yx and inductively via [x, _( n+1) y]=[[x, _( n) y], y]. In this paper we show that necessary and sufficient conditions for RG to satisfies [x^m(x, y), _( n(x, y)) y]=0 is: 1) if r is a power of a prime p, then G is a locally nilpotent GROUP and G' is a p-GROUP, 2) if r=0 or r is not a power of a prime, then G is abelian. In this paper, also, we define some GENERALIZED Engel conditions on GROUPs, then we present a result about unit GROUP of GROUP algebras which satisfies this kind of GENERALIZED Engel conditions...