Perpetuity growth method

Computing terminal value as the final year's cash flow grown one more period and divided by the discount rate minus the perpetual growth rate.

The growth rate itself is the hardest call. Nothing can grow faster than the economy forever, because it would eventually become the economy. So a perpetual rate above long-run nominal growth is arithmetically impossible. And that's only a ceiling. The working range is lower. Rupee models commonly cap perpetual growth at 4% to 5% nominal, because few companies hold their share of the economy forever, and for a mature American business 2% to 3% is the usual range.

This formula also explodes as growth approaches the discount rate. Keep the ₹400 crore final-year flow and the 11.5% rate, and move perpetual growth from 4% to 6%. Terminal value goes from ₹5,547 crore to ₹7,709 crore, a rise of 39%, bought with two points of an assumption about a year nobody will live to check. If a model needs the 6% to justify the current price, it's telling you something about the price.

Cap the rate, then test what the price implies.