Yes several Bollywood real siblings have acted together in a film.
1) Bobby Deol and Sunny Deol
They had together around 6 movies
Dillagi (1999), 23rd March 1931: Shaheed (2002 movie, Apne (2007), Yamla Pagla Deewana series, Poster Boys (2017)
2. Khan Family
a) Salman Khan and Arbaaz Khan
acted together, Garv: Pride and Honour 2004, Dabanng Series, Ready (2011), Pyaar Kiya To Darna Kya (1998, Hello Brother (1999), Maine Pyaar kyun kiya,
b) Arbaaz Khan Khan and Sohail khan
Arbaaz Khan and Sohail Khan acted together in these movies Hello Brother (1999), Kisaan (2009), Jaane Tu. Ya Jaane Na (cameo appearance together)
Also Sohail Khan directed Pyaar Kiya Toh Darna Kya, where Arbaaz Khan acted.
c) Salman Khan and Sohail Khan
Maine Pyaar Kyun Kiya, Veer, Salaam-e-Ishq, Main Aurr Mrs Khanna, Heroes, God Tussi Great Ho, Tubelight
Also, Sohail directed Salman in Pyaar Kiya To Darna Kya, Hello Brother, Jai Ho
•About 3 brothers
Yes, the three real-life brothers, Salman Khan, Arbaaz Khan, and Sohail Khan have appeared together in some films/projects., especially cameos, directing
Examples-Hello Brother (directed by Sohail Khan, Dabangg 3, Hello (Salman had a cameo)
Sohail Khan have directed film of Salman Khan
Iconic scene where Salman Khan and sohail acted in Tubelight film (2017)
3. Farhan Akhtar & Zoya Akhtar
From Luck By Chance and Zindagi Na Milegi Dobara to Dil Dhadakne Do, this brother-sister jodi has received lots of love, Recognition from the audience. They make a really good director-actor duo.
4. Shahid Kapoor and Ishaan khatter
They had acted in 2 movies in Vaah! Life Ho Toh Aisi! And Udta Punjab
5. Shraddha Kapoor & Siddhanth Kapoor
The Kapoor siblings appeared in the film, Haseena Parkar together. They did a really amazing job by playing Haseena and Dawood Ibrahim.
6. Aditya Roy Kapur & Kunaal Roy Kapoor
They both acted in Yeh Jawaani Hai Deewani, Avi played by Aditya in Yeh Jawaani Hai Deewani. But remember Taran, Aditi’s partner in the film? played by Kunaal, Aditya’s brother