Former soldier Billy Irving, 33, from Connel in Argyll, was among six Brits arrested after local police caught them allegedly illegally carrying weapons when their boat, the US-owned MV Seaman Ohio, docked in Tamil Nadu in October.
The vessel had come into shore to shelter from a typhoon.
The men are all employed by private US security firm AdvanFort and had been hired to protect ships in the Indian Ocean from pirates.
Bail had been refused on a number of occasions, but Advanfort said a judge had now ordered their release and the company would pay an undisclosed amount in bail.
The men currently remain in custody.
In a statement, the company said: "The most urgent and compelling interest for all involved - including the families of the captives, the AdvanFort Company and most importantly the guards and crew themselves - has been to release them from confinement.
"The AdvanFort Company sends a special note of thanks to their loved ones for their patience and understanding as we continue to press on 24/7, across ten time zones, to secure their full release."
Mr Irving's brother, Jamie, said his family were delighted and hoped Mr Irving would be home soon.
Mr Irving's family and girlfriend, Yvonne McHugh, had previously called on the Foreign Secretary William Hague to help free the prisoners.