  It is known that realignment crierion is necessary but not a sufficient
criterion for lower as well as higher dimensional system. In this work, we
first consider a two-qubit system and derived the necessary and sufficient
condition based on realignment operation for a particular class of two-qubit
system. Thus we solved the problem of if and only if condition partially for a
particular class of two-qubit state. We have shown that the derived necessary
and sufficient condition detects two-qubit entangled states, which are not
detected by the realignment criterion. Next, we discuss the higher dimensional
system and obtained the necessary condition on the minimum singular value of
the realigned matrix of $d\otimes d$ dimensional separable states. Moreover, we
provide the geometrical interpretation of the derived separability criterion
for $d\otimes d$ dimensional system. Furthermore, we show that our criterion
may also detect bound entangled state. The entanglement detection criterion
studied here is beneficial in the sense that it requires to calculate only
minimum singular value of the realigned matrix while on the other hand
realignment criterion requires all singular values of the realigned matrix.
Thus, our criterion has computational advantage over the realignment criterion.
