Over 2,000 people, including top stars, directors and other film personalities, are expected to converge at Rameswaram island, which is in close proximity to Sri Lanka.
The rally will demand a halt to the island army's ongoing offensive in the north of the neighbouring republic, industry sources said.
Hectic arrangements are underway for staging the rally and the industry personnel would travel to the pilgrim town of Rameswaram by a special train from Chennai, they said.
The move, ostensibly aimed at pressuring the Centre to arrange a ceasefire between the Army and the Liberation Tigers of Tamil Eelam, is spearheaded by Director Bharathiraja and comes after the steady revival of the Sri Lankan Tamils issue in the past few weeks after a gap of 17 years.
Political parties, gearing up for next Lok Sabha polls, are attempting to whip up support for the ethnic Tamils apparently to make the emotional issue a poll plank.
The support for Sri Lankan Tamils gathered momentum as the island's army made successful forays into the Tigers' last stronghold of Killinochi, cornering LTTE chief V Prabhakaran and a vast network of his militant group.
However, unlike the Hogenakkal issue in which the film industry put up a united show in April to oppose the attempts by Karnataka to stall the drinking water project for two border districts in Tamil Nadu, differences have come to the fore over the Rameswaram rally.
A section of actors has expressed reservations over participating in the agitation.
Some actors and artistes are apprehensive about the choice of the venue for the rally as they feel it would be difficult to make themselves available at a far-off place at short notice.
"We are apprehensive about the security of the artistes. Besides, how many people can be accommodated in the small town," an actor speaking on condition of anonymity told PTI.
"In fact, the South Indian Artistes' Association had on Sunday only expressed its moral support to the rally but had not confirmed on its participation," the actor said.
Bharathiraja, on the other hand, had defended the decision to hold the rally in Rameswaram, saying "The island is known throughout the nation and the world and our voice from here will be heard in Sri Lanka."
There is no word yet on the participation of matinee idols Rajnikanth and Kamalahaasan in the rally.
The industry grapevine has it that Rajnikanth may play safe by absenting himself as he might not like a repeat of the Hogenakkal hunger strike that landed him in trouble both in his home state of Karnataka as well as Tamil Nadu.
Kamalahaasan, who had shared the stage with Rajnikanth and others during the film industry fast over the Hogenakkal issue, too has been silent on the issue. Sources close to the actor told PTI he was busy with his next venture Marmayogi.
However, the actor's pro-Tamil sentiments were well known, they said hinting that he may pitch in at the last minute as Rameswaram was close to his native town of Paramakudi.
Actor-politician Vijaykant appears to be another doubtful for the rally as it comes just a day after the youth conference of his DMDK in Chennai.