Central Mine Planning & Design Institute IPO GMP indicate double-digit listing gains— 10 key things to know from RHP by Live mint | March 17, 2026 1:04 pm | Indian Stocks, Market, News Coal India-backed Central Mine Planning & Design Institute’s IPO will open for public subscription from Friday, March 20, to Tuesday, March 24. The issue is entirely an offer for sale (OFS) of 10.71 crore shares of face value of ₹2 each.