The six security officers, three of them from the North East and North Yorkshire, who've been detained in India for four years, will find out next Monday if the appeal against their sentence has been successful.
Nick Dunn from Ashington, Paul Towers from near York, and Nicholas Simpson from Catterick were working as security guards on an anti-piracy ship.
The group, known as the Chennai Six, were given a five-year sentence last year for carrying illegal weapons.
The group have always maintained they had permission to have the weapons.
Their families have continued to campaign for their release.
The Chennai Six
All the men had been working for US maritime company AdvanFort providing anti-piracy protection when their ship, MV Seaman Guard Ohio, was detained and weapons found.
They were arrested in October 2013 on illegal weapons charges.
The charges were dropped in the following months, but an appeal followed from the Indian authorities and in 2016 they were convicted and sentenced to five years in jail.