Hi, dont know if the Indian Il-76's will turn up, however you are correct about the rumour!
They are supposed to be bringing in the Drew (?spelt correctly?) helicopters, however they are currently grounded due to an issue with the tail rotors so this may not happen. However the rest of the Indian displays participants will need to be shiped in also so just keep your fingers crossed.
However, IF they do turn up it does not mean they will be at RIAT!
Cheers, D