Comment on Zerodha - Plan of Action - FY 2014/15
If you’ve placed an SL-M order, there’s no reason for the order to not get executed, however since its a market order there’s bound to be some slippage, more so if it’s an illiquid contract. If you’re placing an SL order, it would depend on whether your limit price was reached.
No broker in the world can guarantee execution, since the orders are matched and traded at the Exchange level.