You can start FnO trading on Groww in these simple steps:
1. Login to your Groww account
2. Click on the F&O option available right below the "top gainers"
3. You will see 'option chains' which will take you to the available contracts
4. After you've chosen the contract, click on your preferred call option
5. You can also see the "buy" and "sell" option to buy/sell an order
For detailed information, you can refer below