Nice gun, Most likely 308 version will be the one India picks, 338LM could be a possibility, creedmoor is doubtful, although is a wonderful round.
Nice rifle. I own a civilian version.
What caliber is Indian getting? .308 or 6,5 Creedmoor? The 6,5 is better for long range, though a tad light for seal hunting, but outclasses the venerable .308 any day. I'm not sure if the Tikka T3x has the option of a .338 conversion though.