  Stellar components in binaries are subject to tidal forces which influence
asteroseismic properties. Tidally pertubed pulsations have been reported for
different objects but none of these are in their pre-main sequence phase of
evolution. This makes RS Cha, consisting of two $\delta$ Scuti stars and with
pulsational characteristics influenced by tidal effects , the first such object
observed. We aim to investigate the pulsational properties of the eclipsing
binary RS Cha in terms of the theory of tidally perturbed pulsations. Based on
photometric time series obtained from the TESS satellite, we performed binary
modelling using PHOEBE to interpret the binary light curve and to allow the
investigation of the pulsations of both components in RS Cha. We modelled the
detrended light curve with the superposition of linear modes. The frequencies
were then interpreted as self excited modes perturbed by tidal forces. We find
evidence for tidally perturbed modes, which enables the identification of
pulsation modes. RS Cha mainly exhibits dipole modes, while one prominent $l=2$
or $l=3$ mode is also inferred. The latter verifies previous results from
spectroscopic time series. This work shows that RS Cha is an ideal candidate to
test the theory of tidally perturbed pulsations within the framework of
asteroseismic modelling. The identification of multiple pulsation modes using
this theory is unprecedented and will be a keystone in the future of pre-main
sequence asteroseismology. However, amplitude modulation caused by the changing
light ratio during the orbital phase in an eclipsing binary also plays a
significant role, which can complicate mode identification.
