Can I buy and sell shares across the two exchanges?
You will be able to place an MIS buy order in one exchange and an MIS short order in the other and vice versa.
If you hold shares of a company which trades in both the exchanges, you can sell it on one exchange and buy it back on a different exchange. The brokerage charged will be that of an intraday trade. However, for the purpose of STT, it will be considered as a delivery trade.
You will be able to buy in one exchange and sell in the other after you get delivery for the shares i.e T+2 days.