What does this error mean - “RMS: rule: check trigger price vs ltp for sl-m orders; Trigger price: 351. 50, ltp 352. 50 for entity account-XXXXXX across. ”?

On 12th Jan,17 before market open, IOC Jan Fut prev close price was Rs 347-348 approx. As I want to buy IOC Jan Fut ONLY IF the price goes above 351.50, I placed SL-M BUY ORDER with TRIGGER PRICE of Rs. 351.50 (thru AMO since the timing of order placement was 9.05 AM).Although the IOC Jan Fut opened at 351.50, this order was rejected after Market OPENS today (9.15AM) with below message:“RMS: rule: check trigger price vs ltp for sl-m orders; trigger price: 351.50, ltp 352.50 for entity account-XXXXXX across.”

When you place an SL-M buying order, there is a validation to check if your trigger price is above or below the market price. Sl-M buying orders can be placed only if trigger price is above the current price. Because if it is below, it gets triggered immediately and becomes like a normal market order.When you use SL-M as AMO, when the order hits the exchange, if your trigger price is below the LTP (the first few ticks of the day when the market opens), the order gets rejected with the same validation reason mentioned above. This can happen when the stock has opened with a gap.You place an SL-M with trigger at 351.5 as AMO, this order is sent to the exchange only after 9.15am.The market opens up above 351.5. Your order is now placed, validation is done to check if your price is below the market price since it is, it gets rejected. There is no way around it for now. If we don’t have this validation, most of the clients who use SL-M during market might end up making mistakes.

While the explanation given by Bhuvanesh seems logical, there is one point that contradicts. The market opens @9:!5am and you are calling a price set in the pre-session time as LTP - Last Traded Price. How can the opening price be termed as Last Traded Price. Trading happens only after the market opens.
Also one would set AMO orders bases on the closing price of the day (OR previous day). And the concept of TRIGGER PRICE is defeated by this RULE. The TRIGGER price says that if market goes beyond the TRIGGER price even by an opening gap the order is supposed to be filled. Then why are these orders being rejected ?.

What kind of mistakes are you referring to when you say that “Clients might end up making mistkaes”.