The entitlement ratio is very difficult to predict. The number quoted in broker/investment bank reports. which is 59%, was calculated based on the data available as on March 31st 2017. Over the past 8 months, this could have changed significantly. Unlike previous buybacks, the Infosys buyback received large scale coverage, so much so that many brokerage firms sent their clients a special note recommending purchasing Infosys purely as a buyback play.
One thing is for sure; the more time Infosys takes to send out the tender forms, the higher will the acceptance ratio be. If it takes a long time like the Wipro buyback, a large number of retail investors would lose patience, sell the stock and deploy their funds elsewhere, thereby increasing the acceptance ratio for the rest.