 About 60 percent of the hydrographic stations show negative bias for collected river 12 discharge. 13  Nearly 80 percent of the hydrographic stations show good skill with significant mean 14 absolute error at few stations. 15  The assessment shows a good skill for Ganges-Brahmaputra and the lowest for Pennar and 16 Cauvery river basins. Abstract 18 A significant task in river hydrology is to envisage the river’s present, past, and future 19 environments. India has some of the world’s major river basins, including Ganges-Brahmaputra, 20 Mahanadi, Krishna, and the Godavari produce an enormous amount of water as river discharge 21 alongside turbidity into the Bay of Bengal. The revised Kling-Gupta efficiency skill score 22 (KGESS) has been used to determine the performance of reanalysis river discharge. The skill of 23 reanalysis discharge was found admirable for the Ganges-Brahmaputra river basin (KGESS = 0.86 24 > 0), with notable mean absolute error and high correlation coefficient (0.94). Furthermore, 25 Subarnarekha, Brahmani-Baitarani, Mahanadi, Godavari, Krishna river basins, and the rivers 26 flowing between Mahanadi and Pennar Rivers exhibit moderate to good skill. However, Pennar, 27 Cauvery, and the rivers flowing between Pennar and Kanyakumari show the lowest skill. 28 Approximately 60% hydrographic stations of river catchments demonstrate that reanalysis 29 discharge is negatively biased (i.e., bias < 1). Nearly 58% hydrographic stations show lower 30 variability (i.e., variability ratio < 1) with the median value of 0.91 and the interquartile range 31 (0.82, 1.13). Moreover, the overall median of the Pearson correlation coefficient was 0.73 with 32 interquartile ranges between 0.51-0.83. The reanalysis and observed datasets show a significant 33 change in river discharge throughout the southwest monsoon and less in the post-monsoon period. 34 Concurrently, some hydrographic stations show a significant increase in river discharge during 35 post-monsoon in Pennar and Cauvery River basins. 36 37