There’s no straight forward way to determine this. Ideally, your broker is required to pass on all benefits accrued to the client and not book such gains in their own books. You wouldn’t want to trade with a broker who you don’t trust.
The issues here are: Say, you’re a client who has a receive delivery position, while there’s another client of the broker who has a give delivery position in the same stock. At the Exchange level, positions are net off at broker level. So 1 long position and 1 short position between 2 different clients of the same broker get net off and there’s no shares to receive/deliver from/to the Exchange. The broker is required to internally settle these trade by debiting the selling client and crediting the buying client. In such a case, if the selling client doesn’t delivery, the broker has to carry out the settlement of trades usually through an internal policy that he may have. At Zerodha, we buy shares in our account, transfer the debit fund obligation to the client who sold but did not deliver shares and credit the shares to the buyer who did not receive. The buyer receives shares with a 1 day delay.
But if there’s no internal netting off, there’s a way to determine if the broker passed you the 20% close out credit or not. When the Exchange has to credit shares to a broker’s pool account, it always does it with a ‘settlement number’ tag. When the shares are then transferred to your account, the settlement number shows up in your demat statement. Each trading day of the week is assigned a unique settlement number. Likewise, the settlement numbers for shares under ‘physical delivery’ payout are also defined.
Now to determine if your broker bought shares and credited it to you instead of passing on the 20% benefit, here’s how you can figure:
(a) Ask your broker to send you your ‘statement of transaction’ for the demat account to which you’ve received the shares
(b) Every demat credit in the statement, will have an accompanying settlement number from where shares are transferred
('c) If the payout of SBIN was received from an auction for physical delivery shares, the respective settlement number would show up in the statement. (you may have to refer ICCL’s settlement numbers if your broker is clearing through ICCL).
(d) If the payout of SBIN is received in regular settlement, then you can sort of conclude that the transfer was made from purchase of shares by the broker. Do ask with your broker about this anomaly if exists.