Rights issue and the divisor

An index has free-float capitalisation ₹30,00,000 crore and stands at 25,000. A constituent with $N = 100$ crore shares, IWF 0.6 and cum-rights close ₹900 makes a 1:4 rights issue at ₹600, fully subscribed. (a) Compute the TERP. (b) Compute the change in free-float capitalisation and the new divisor (assume the IWF is unchanged). (c) Explain why a split needs no divisor change but a rights issue does.