What a shareholding pattern can and cannot tell you

Business Standard reported that Rakesh Jhunjhunwala first appeared in Tata Motors' shareholder list in the September 2020 quarter with 4 crore shares (about 1.29%), worth about ₹500 cr in October 2020. (a) What per-share price does "₹500 cr for 4 crore shares" imply, and why is this not his cost? (b) Design an estimation procedure that gives an honest range for his average cost from public data. State every assumption, and list what the range cannot exclude. (c) Write down, in advance and in falsifiable form, three observations that would constitute "permanent impairment of value" for a cyclical auto company, in the sense of his Titan quote.