  In this work we demonstrate that the polycrystalline ribbons of
(Ni48Co6)Mn26Al20 with B2 structure at room temperature show a magnetic
behavior with competing magnetic exchange interactions leading to frozen
disorders at low temperatures. It is established that by considering the
presence of both antiferromagnetic and ferromagnetic sublattices, we can
explain the observed magnetic behavior including the metamagnetic transition
observed in these samples. From the Arrott plots, the N\'eel temperature of
(Ni48Co6)Mn26Al20 is deduced to be ~170 K and the broad ferro to para like
magnetic phase transition is observed at ~ 200 K. Based on N\'eel theory, a
cluster model is used to explain the presence of ferromagnetic and
anti-ferromagnetic clusters in the studied ribbons. Formation of ferromagnetic
clusters can be understood in terms of positive exchange interactions among the
Mn atoms that are neighboring to Co atoms which are located on the Ni sites.
