Corporate actions are of two types; cash and non-cash. Since you can hold equities and bonds in your demat account, you will get cash payouts in the form of interest and dividends. These will get directly credited to your bank account and you need to do bank reconciliation for the same. Then there are non-cash corporate actions like bonuses and stock splits which are automatically credited to your demat account. The onus is on you to check these things constantly and keep a check list of corporate actions. If you find any discrepancy in this regard, you will have to directly contact the Registrar and Transfer Agent (RTA) to get the same resolved.