Vodafone Idea, the country’s largest telecom operator, on Wednesday said its board has approved raising of up to Rs 25,000 crore through rights issue. The issue will open on April 10 and will close on April 24. The promoter shareholders (Vodafone Group and Aditya Birla Group) confirmed their participation of up to Rs 11,000 crore and up to Rs 7,250 crore respectively; in excess of their combined current entitlement.