Her father K K Madhavan, a former CPI(M) local leader, is accompanying her to Thiruvananthapuram.
Before leaving for the state capital, Rema told reporters that the fast will commence at 10 AM tomorrow and that she was hopeful that Opposition leader V S Achuthanandan would visit her at the fast spot.
At least 50 Revolutionary Marxist Party workers will go on relay fasting along with Rema.
A Kozhikode court had on Jan 28 sentenced 12 persons, three of them CPI(M) functionaries, to life imprisonment in the case.
Chandrasekharan, a former Marxist worker from the red bastion Onjiyam near Vatakara in north Kerala, was hacked to death by an eight-member gang on May 4, 2012. There were 51 hack wounds on his body.