Abstract : | We present high-precision interstellar dispersion measures and time-of-arrival (ToA) residual estimates for eight millisecond pulsars (MSPs). These MSPs are chosen from the pulsar timing array sample for the detection of nanohertz gravitational waves. The time baseline of the current data release spans over 3.5 years of data obtained using the upgraded GMRT as a part of the Indian Pulsar Timing Array (InPTA) experiment. It is the first official data contribution from InPTA towards the International Pulsar Timing Array besides NANOGrav, European Pulsar Timing Array and Parkes Pulsar Timing Array. The dataset forms the basis of our recent studies and findings including the 2021 profile change event in PSR J1713+0747, the detection of solar coronal mass ejection from DM excess in timing measurements of PSR J2145-0750, the investigation of scatter broadening in low frequency profile of PSR J1643-1224, the determination of dispersion measures and ToA residuals in multiple pulsars using the wideband timing technique, frequency dependence of decorrelation bandwidths and single pulsar noise modelling. |