Hum Dono
Raja (Rajesh Khanna) discovers that his face is similar to that of Dr. Shekhar, one of the top earning doctors of Bombay. He somehow manages to take his place, but discovers that even Dr. Shekhar has problems of his own.
Starring Rajesh Khanna, Hema Malini, Reena Roy, Johnny Walker, Jagdeep, Om Shivpuri, Keshto Mukherjee, Asit Sen, Shubha Khote, Birbal
It's a family and comedy movie, and has a rating of 6.7 out of 10 from Imdb which is usually fine for this kind of movie.
Watch it here
Not found streaming from India.