The 26-year-old actor also shared that she is "petrified" to shoot for the film, which will be directed by her father and filmmaker Mahesh Bhatt.
"Today is Day 1 of Sadak 2. And that's my father, now also my director, holding the clap. I begin shoot in a few days and honestly, I'm petrified," she began her post.
"I feel like a tiny mouse trying to climb a beautiful, immense, emotional mountain.
I hope I make it to the top and if I fall I hope I'm able to get up again," she added.
The 'Brahmastra' actor said that it is a "tough climb".
"It's a tough climb but from everything I've seen and everything I've heard, I know every single step and misstep will be worth it," she said.
Aditya Roy Kapur's "bikini body" post making celeb-friends go ROFL! Ranveer, Alia & others REACT!
She further said, "Here's to movies, family, dreams and starting out on a brand NEW journey! And what a journey it's going to be."
Take a look at her post below:
Alia Bhatt on Mahesh Bhatt: My father is Youth Icon of Year
As Alia shared the photo, actor Dia Mirza wrote "All the BEST Alia!!! This is going to be so so so special", while Bipasha Basu commented "All the best".
In September 2018, Alia took to social media to announce that she will be collaborating with her father for the first time in his upcoming directorial venture 'Sadak 2'. The film will also mark his return to directing films in Bollywood after a hiatus of almost twenty years.
Following Alia's announcement, Vishesh Films also shared a one-minute teaser revealing the cast and release date of the highly-anticipated film.
The 'Highway' star will be sharing screen space with Sanjay Dutt, Pooja Bhatt, and Aditya Roy Kapur in the much-awaited film.
The 1991 blockbuster 'Sadak' starred Sanjay Dutt, Pooja Bhatt, Sadashiv Amrapurkar, Deepak Tijori, and Neelima Azeem. The original film was a romantic thriller and revolved around the life of a young man who falls in love with a sex worker.
The upcoming film is slated to hit the big screens on March 25, 2020.