The Ek Deewana Tha stars gave blood at an event held at the Narsee Monjee Management College.
Jackson posted on Twitter: "At NM College to support Drishti and Being Human for their Registering Camp for Bone Marrow!! Such a good cause (sic)."
The UK model and Tamil cinema star requested that her fans also donate blood.
"Drishti rocks! Just become a blood donor with TATA Memorial Hospital...Donated blood today. Make sure you do the same and make a difference!" she wrote.
Jackson's co-star Prateik added: "Donating 10ml or 2 teaspoons of blood could potentially add 20+ years to a Cancer patients' life...Small activity 2day can mean a LIFE 2moro."
The movie's AR Rahman soundtrack was unveiled in December at the Taj Mahal.
Ekk Deewana Tha releases on February 17, 2012.
Watch the theatrical trailer below: