Role in the film
Antoc Merric is known as the Blue Leader. He leads the Blue Squadron of the Rebel Alliance. When a rebel officer announced that Jyn Erso and the rest of the members of Rogue One attacked on Scarif to steal the Death Star plans, Merrick and his members attacked on the planet itself.
During the battle, the planet itself has a shield gate and Merrick and some of his members entered the gate while the rest didn't enter when some of the Imperial officers closed the shield gate.