I am aware of Gill but he is very young. But Vihari has a phenomenal first class record, he can’t have earned that without having the tools. He also got a stinker of a decision.
Rahane has hundreds every where, you don’t throw that away.
Vihari might have a great fc record but he was pretty hopeless when the Aussies bombed him with the chin music. As for Rahane, yes in the past he scored runs everywhere, but in his last 40 innings he's scored a solitary century.
Gill is about to reach 1000 fc in a mere 15 innings and despite the small sample size he got an eye watering average above 80!
India have a few Test against weaker opposition before the head to New Zealand next year for Tests, it's the correct time for a youngster like Gill to get his opportunity.