We present results from our search for H i 21-cm and OH 18-cm absorption at z \sim 1 - 1.4 towards red quasars showing strong Mg ii absorption using uGMRT .
The quasars J1501 + 1822 and J1521 + 5508 show multiple strong associated Mg ii absorption at z \sim 1.1 and signature of reddening in their optical spectra .
We report the detection of H i 21-cm absorption towards J1521 + 5508 at the systemic redshift of the quasar , with N ( H i ) = ( 1.2 \pm 0.2 ) \times 10 ^ { 20 } cm ^ { -2 } for spin temperature of 100 K and unit covering factor .
The H i 21-cm absorption is offset from the blueshifted strong Mg ii absorbers by \gtrsim 1500 km s ^ { -1 } .
We do not detect H i 21-cm absorption at the redshift of the associated Mg ii absorption and at the systemic redshift towards J1501 + 1822 .
We argue that lack of one-to-one correspondence between Mg ii and H i 21-cm absorption could be related with clumpiness of the neutral gas and the radio and optical sightlines probing different volume of the gas .
We find that the presence of strong associated Mg ii absorption and reddening in the optical spectra of the quasars lead to an increased detection rate of associated H i 21-cm absorption at z \geq 1 .
We also report non-detection of intervening OH absorption ( [ OH ] / [ H i ] \leq ( 1-4 ) \times 10 ^ { -8 } ) at z = 1.3 towards two red quasars , J0850 + 5159 and J0852 + 3435 , which show strong metal and H i 21-cm absorption and the 2175 Å dust extinction bump .