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We present the results obtained from broadband X-ray timing and spectralanalysis of black hole candidate MAXI J1803-298 using an AstroSat observationon May 11-12, 2021. Four periodic absorption dips with a periodicity of $7.02\pm 0.18$ hour are detected in the light curve. AstroSat observe the sourcewhen it was undergoing a transition from hard-intermediate state tosoft-intermediate state. Our timing analysis reveals the presence of a sharptype-C quasi periodic oscillation (QPO) in the power density spectra (PDS) withan evolving QPO frequency ranging from $5.31 \pm 0.02$ Hz to $7.61\pm 0.09$ Hz.We investigate the energy dependence of the QPO and do not find this feature inthe PDS above 30 keV. The combined $0.7-80$ keV SXT and LAXPC spectra arefitted with a model consisting of thermal multi-colour blackbody emission andComptonized emission components. We perform time-resolved spectroscopy byextracting spectra during the dip and non-dip phases of the observation. Aneutral absorber is detected during the dip and non-dip phases though asignature of an ionized absorber is also present in the dip phases. Thespectral and temporal parameters are found to evolve during our observation. Weestimate the mass function of the system as $f(M) = 2.1-7.2~M_{\odot}$ and themass of the black hole candidate in the range of $M_{\rm BH} \sim3.5-12.5~M_{\odot}$.

AstroSat Observation of X-ray Dips and State Transition in the Black Hole Candidate MAXI J1803-298