The 44-year-old actor took to Twitter, where he posted a black-and-white picture from his childhood which shows him, his father and younger brother Akshaye enjoying a day-out on the beach.
"Feels like yesterday," Rahul captioned the photo.
Khanna had Rahul and Akshaye, 42, from his first marriage with Gitanjali but got divorced in 1985.
The "Imtihan" actor married Kavita in 1990 and has two children - son Sakshi and daughter Shraddha with her.
He died at the age of 70.
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