The correct options are
B He convinced many Sardars to support his Chhatrapati.
C He convinced Kanhoji Angre to support Sahu Maharaj.
Shahu Maharaj and Maharani Tarabai were supported by different Maratha Sardars. Maharani Tarabai was supported by Kanhoji Angre who attacked the territories of Shahu Maharaj. In response, Shahu Maharaj sent Balaji Viswanath to fight against Kanhoji. However, like other Sardars, Balaji won over Kanhoji without war and convinced him to support Shahu Maharaj.