No it's not.
Our gap is non existent.
Rafales will arrive in 2017, won't be operational until 2019 due to training, doctrine issues.
T-50 is in bad weather, Russia has no money & is lacking in technology to deliver it in time. As things are going IAF won't have operational T-50 before 2020-21
Our sixteens & seventeens plus SAMs, AWACs can do their primari job just fine till 2020, we don't need a new platform. More Block-52s are welcomed, however another solution would be to buy 60 odd Norwegian sixteens and put them through SABR F-16V AESA upgrade. 60 odd AESA upgraded F-16s will give us equal capability to Rafale, in strong numbers.
FC-31 is a great prospect. We ought to join the program along the lines of JF-17 Thunder program. I expect it to be operational around 2020-21 timeline.
@araz