Futures and Options (F&O) contracts are available only for a subset of listed securities (WEB) on the exchange along with a few indices, namely Nifty, Bank Nifty, Nifty Midcap select, FinNifty, Bankex and Sensex.
If the F&O contract isn't showing up even after you type the name correctly, the stock may not be allowed for trading in the F&O segment, as SEBI has specific rules for inclusion.