Edtech billionaire Ronnie Screwvala believes that in the next four years there will be five to six edtech companies in the world with valuations of $40-50 billion each. More importantly, at least two or three of them will be India-based. So, he and his team, according to sources, are working aggressively to get into this coveted list.   Is he being overly ambitious?  His higher education and professional upskilling start-up upGrad joined the unicorn club only in August this year with a valuation of $1.2 billion, some distance from the magic number and from most of his competitors.