One observation by me. Airtel (and VodaIdea) both filled up the gap of 56-day plan which was not existing earlier. However, what they wisely did was, price the plan Rs 399, same as Jio, with data benefits same as Jio (1.5GB/day), but included all Unlimited off-net calls as well. This again puts the ball back into Jio's court. Will Jio reduce the cost of Rs 399 plan now?
Also, a simple math shows that the Rs 599 plan for 84 days is now redundant. Because, (Rs 399 for 56 days) works out to be Rs 199.5 / 28 days, and (Rs 599 for 84 days) works out to be Rs 199.67 / 28 days. Usually, a higher commitment plan should be cheaper, but with the new plan launch, this is not the case, I dont see any case wherein anyone would not opt for Rs 599 / 84 days (unless for convenience).