  In the context of higher dimensional braneworld scenario, we have argued that
the occurrence of horizonless exotic compact objects, as an alternative to
classical black holes, are more natural. These exotic compact objects carry a
distinctive signature of the higher dimension, namely a tidal charge parameter,
inherited from the projection of the higher dimensional Weyl tensor onto the
four dimensional spacetime we live in. Due to the absence of any horizon,
rotating exotic compact objects are often unstable because of superradiance.
Interestingly, these higher dimensional exotic compact objects, in the presence
of the tidal charge, are more stable than their four dimensional counterpart. A
similar inference is drawn by analysing the static modes associated with these
exotic compact objects, irrespective of the nature of the perturbation i.e., it
holds true for scalar, electromagnetic and also gravitational perturbation. The
post-merger ringdown phase of the exotic compact object in the braneworld
scenario, which can be described in terms of the quasi-normal modes, holds
plethora of information regarding the nature of the higher dimension. In this
connection we have discussed the analytical computation of the quasi-normal
modes as well as their numerical estimation for perturbations of arbitrary
spin, depicting existence of echoes in the ringdown waveform. As we have
demonstrated, the echoes in the ringdown waveform depends explicitly on the
tidal charge parameter and hence its future detection can provide constraints
on the tidal charge parameter, which in turn will enable us to provide a
possible bound on the length of the extra dimension.
