It is only applicable when Base condition is True for given Recurrence Relation.
Master theorem can apply to any recurrence relation if it has following format,
$T \left ( n \right ) = a T \left ( \frac{n}{b} \right ) + n^{k}log^{p}n$
where, $a \geqslant 1, b > 1, k \geqslant 0$
and P is read number.