The Indian Supreme Court has told the men the case will be re-opened and re-examined.
A previous judgement found the seafarers had no charges to be answered.
Twenty-one months ago the men, who work as anti-piracy support teams in international waters, were arrested after India alleged the men were in Indian waters in an armed vessel.
Christian charity Mission for Seafarers has been supporting the men, who have been held on suspicion of terrorism offences, illegal bunkering (refuelling) and storing guns.
The men deny all charges.
Revd Canon Ken Peters, from Mission for Seafarers, told Premier: "Prayerful support is absolutely essential, we need to get that right. We need to get as many people in their prayers thinking of these men, 35 of them - only six are Brits, there are 12 Indians, 14 Estonians and three Ukrainian.
"The men of course, having not been paid for almost 21 months, need the accommodation and subsistence, so financial support is also accepted.
"The men were fully expecting the Supreme Court Judgement to uphold that of the High Court and send the men home.
"That has not happened and for the men it's devastating - the families are distraught and the pastoral care - well there's even more need for it now.
"Families are in a terrible mess, one baby's been born, children are growing up having not seen their father for 21 months and longer, the situation is just appalling."
Listen to Premier's Hannah Tooley speak to Revd Canon Ken Peters here:
