As of I know there are no charges for account closing. When it comes to the procedure, it depends on the broker. Few brokers are allowing the customer to close the account online and few are demanding in-person application. But before closing the account you must be clear about the following things

• There must not be negative balance in your trading account, if so you must clear before closing
• Make sure you don’t have any holdings in your demat account
• You have to close your demat and trading account at once. You are not allowed to use trading account without demat account.

Each broker has a specific procedure. Contact your broker for support.