The actress said she was contacted over Facebook by Yash Raj Films' casting team after they failed to reach out to her over her mobile phone and feels she was quite "lucky".
"The (YRF) team was trying to get in touch with me on my old number. They then finally wrote to me on Facebook," Sayani told PTI.
"When I auditioned for 'Fan', I was not aware it will have Shah Rukh Khan in it. After auditioning for two months I got a call from Shanoo Sharma (of YRF) that I have been selected. That's when they told me about the film and SRK playing the lead. It just hit me," she said.
Apart from "Fan", the actress also has big projects - Ranbir Kapoor and Katrina Kaif's "Jagga Jassos" and Sidharth Malhotra-Katrina's "Baar Baar Dekho".
"It's like a dream that I am living. I feel fortunate, blessed and lucky to have been part of these three big films. My role in all these films is interesting," she said.
"I am happy to be working with talented directors and actors. I have really worked hard to reach here and get interesting work. I used to give over eight-nine auditions in a day."
Recalling her experience working in "Fan", the "Margarita, with a Straw" actress said she was amazed with Shah Rukh Khan's generosity when she first met him.
"He is a simple and sweet man. He doesn't make you feel that he is a star. He is humble, gracious and warm person. It was fun working with him."
"After the first day of shoot he hugged me and said 'baby you are talented you have a long way to go'. I did not expect a comment like this from a superstar like him," she added.
Sayani revealed that she is playing a teenager in Anurag Babu's upcoming comedy-drama "Jagga Jassos", which is likely to release this year in August.
"I know a person who happens to be friends with director Anurag Basu. That's how Anurag sir asked me audition for the film. He liked my performance and chose me. I am playing a 14-year (teen) in the film," she said.
For romantic drama "Baar Baar Dekho", Sayani says she was asked to submit a video audition, which was liked by the makers.
"It's an interesting role," she added.
The film marks the directorial debut of Nitya Mehra and is produced by Ritesh Sidhwani, Karan Johar and Farhan Akhtar.
It will hit screens in September, 2016.