Waah! Tera Kya Kehna (2002)

Kishan Oberoi has three sons - Dilip, Ashish, and Raj. While Dilip and Ashish are married, Raj (Govinda) is in love with Meena. Kishan does not trust his two elder sons, but trusts Raj, and Raj in turn, is devoted to his dad. One day Raj loses his mind in an accident, and the two elder brothers begin a conspiracy that includes the death of their dad, and the disinheritance of their brother Raj, by declaring him mentally incompetent. Raj mysteriously disappears, and Kishan falls off a building; Murari, a greedy employee of the Oberoi family, brings in a look-alike of Raj, namely Banne Khan (also Govinda), and his wife, Salma Khan, who poses as his nurse, so that Banne Khan and Murari both rule over the Oberoi family, and reap the benefits.

Unfortunately the movie Waah! Tera Kya Kehna is not yet available on HBO Max.