  We consider systems of D6 branes in the presence of a nonzero $B$ field of
different ranks. We study the scattering of gravitons in the corresponding
supergravity backgrounds. We show that the nonzero $B$ field does not modify
the form of the scattering potential. The graviton scattering equation has two
solutions one normalizable and one non-normalizable. The normalizable solution
does not lead to an absorption, however the non-normalizable one does. We
analyse the absorption of gravitons by the branes and show that it is nonzero
in the decoupling limit. This result suggests that even in the presence of a
$B$ field the D6 branes worldvolume theory does not decouple from the bulk
gravity. For comparison we analyse the form of the scattering potential and
absorption for Dp branes with $p <5$ and for NS5 branes.
