Sidharth Malhotra as Vivaan Malhotra.
Before:-

Now:-

Vivaan is a successful business man and is the richest bachelor of India. He is very serious about his work and is a very sofisticated person. All girls are mad on him.
But he was a typical chashmish type of a guy during his childhood and teenage.

Alia Bhatt as Girijah Singh.

Before:-

Now:-

She is a top cinematographer and model in Bollywood. She is beautiful and hot. She is wanted by all guys in India and abroad but she has a boyfriend who is the top celebrity actor of Bollywood, Varun Dhawan.

But she was a typical tomboy during her childhood and teenage.

Shah Rukh Khan as Girav Singh. (Father of Girijah).

Kajol Devgan as Aarti Singh. (Mother of Girijah).

Reuben Israel as Vansh Vikram Malhotra. (Father of Vivaan).

Zaira Wasim as Vivaanya Malhotra (Younger sister of Vivaan).