  The seasonal prediction of the Indian summer monsoon (ISM) and Monsoon
Intraseasonal Oscillations (MISO), as well as the Madden Julian Oscillations
(MJO) that strongly modulate MISO, is important to the country for water and
crop management. We have analyzed the precipitation, convection, and total
cloud fraction (TCF) in the sixth Coupled Model Intercomparison Projects
(CMIP6). This study highlights the significant differences in simulating MISO
and MJO between the two groups of selected CMIP6 models and physical reasons
behind them. The mean and intraseasonal features of MISO and MJO varied
significantly in CMIP6 models, which are linked with a better depiction of
convection and total cloud fraction. The probability distributions of rainfall
and OLR in CMIP6 models indicate significant variations in simulating ISM
precipitating clouds. TaiESM1 and IITM-ESM demonstrate improvements in
capturing the MISO features. TaiESM1 depicts better eastward propagation of MJO
during both summer and winter. The biases in OLR and TCF are also less in the
IITM-ESM and TaiESM1 models than in CanESM5 and FGOALS-g3. The results
demonstrate the importance of cloud and convection in CMIP6 models to depict
realistic MISO and MJO and provide a road map for improving ISM climate
prediction and projections.
  Keywords: ISM rainfall, CMIP6 models, MISO, MJO
