Pyaar Ka Rishta (1973)

Balraj Sahni is brother of Nirupa Roy. Sameer is son of Nirupa Roy and Vinod Khanna is son of Balraj Sahni. They both live in a same house but due to difference between Nirupa Roy and Balraj Sahni's wife and Nirupa Roy takes her son to another house. At the end how they unite have to watch Pyar Ka Rishta.