They're unlikely to be used on LoC anytime soon, even after official adoption. Initially, they'll be distributed on an urgent replacement basis, so special force, infantry active against insurgents, ANF...etc. So, any new rifle will probably see combat relatively immediately (post retraining with the new rifles and active deployment), but they'll be used against militants, not against conventional forces.
[Edit]: In fact, I'd say that new rifles won't see active deployment across the LoC for at least 5-8 years, after a final decision on the winning rifle is made.
