"He was admitted to Lilavati Hospital at around 10:30 a.m. He has not been keeping well for quite some time, " the 73-year-old's spokesperson, R.R.Pathak, said.
"His wife Neelam Mukherjee too distraught at the moment, " he added.
Mukherjee, who made his cinematic debut in 1960 with "Love In Simla", became a known face with films like "Shagird", "Love in Tokyo", "Bahu Beti", "Ziddi", "Phir Wohi Dil Laya Hoon", "Ek Musafir Ek Hasina", "Puraskar", "Ishaara" and "Hum Hindustani".
The paternal uncle of actors Kajol and Tanisha, Mukherjee also directed movies like "Love in Bombay" (1974), "Chhaila Babu" (1977), "Saanjh Ki Bela" (1981) and "Umeed" (1989).