Galaxy clusters, the largest gravitationally-bound structures in the Universe, primarily consist of dark matter, offering a unique opportunity for investigating its distribution and behavior. Our study involves an examination of the stellar-to-smooth dark matter mass fraction in the galaxy cluster lensing the quasar SDSS J1326+4806, while concurrently estimating the size of the quasar's broad-line emitting region through microlensing observations. Utilizing GTC spectra, we are assessing the impact of microlensing on the wings of the C IV high-ionization line. Our Bayesian analysis has revealed that the smooth dark matter fraction near image A is ∼88%, and the estimated half-light radius for the C IV emitting region is R1/2=8.1±4.3 light-days.