The Indian students I've met at RVAC have all had perfectly good English, and probably have a better grasp of comprehension, grammar and pronunciation than most Australians.
I seem to recall I wasn't very flash with my voice procedure as a student, I still occasionally get tongue tied and cop a gentle reminder from the YMMB Tower.
On the other hand I've listened to the Tower trying to get some sense out of the students of another school............."Which one are you? Number One, number Two or number Three? Can you waggle your wings for me?"
To put it another way, I'd be surprised if English was an issue.